The German Thrust across Southern Yugoslavia
The XL Panzer Corps, which was to attack across southern Yugoslavia, jumped off at 05:30 on 6 April, thrusting across the Bulgarian frontier at two points. It met strong opposition from an enemy who seemed determined to stop the invaders. The 9th Panzer Division advancing toward Kumanovo was thus delayed along the mountain roads, and the 73d Infantry Division drive toward Stip was held up near Carevo Selo. However, after several hours of fighting, the enemy nests of resistance were reduced, and the first 600 Yugoslav prisoners were brought in from the front. By the evening of the first day of the offensive, the spearheads of the two divisions had reached the area east of Kumallovo and Kocane. During the night strong elements of the 9th Panzer Division closed up and the next day the remaining heavy vehicles crossed the mountain passes near the border. By the afternoon of 7 April the advance guard of the armored division entered Skoplje, almost sixty miles west of the border.
That same day the flying column attached to the 73rd Division reached Veles, while the main body of the division followed at some distance. The reinforced 1st SS Motorized Infantry Regiment, which had been held back, moved up along the 9th Panzer Division route to participate in the assault on the Vardar defense positions.
The continuation of the operation looked hazardous because a force of less than three divisions was to drive deep into enemy territory with both flanks open. The First Panzer Group offensive in the north was not to start until 8 April and no news on the progress of the 2d Panzer Division attack farther to the south was available. Moreover, the possibility of Yugoslav counterattacks against the rear of the panzer corps was not to be excluded. None of these threats materialized.
The Vardar was crossed with surprising ease and the corps thus gained freedom of maneuver. By the evening of 8 April the XL Panzer Corps began its pivoting movement and the advance elements of the SS regiment captured Prilep. The important rail line between Belgrade and Salonika was severed and one of the strategic objectives of the campaign-to isolate Yugoslavia from its allies-was achieved. In addition, the Germans were now in possession of terrain that was favorable for the continuation of the offensive. On the evening of 9 April General Stumme deployed his forces north of Monastir, ready to carry the attack across the Greek border toward Florina. While weak security detachments covered the rear of his corps against a surprise attack from central Yugoslavia, elements of the 9th Panzer Division drove westward to link up with the Italians at the Albanian border.
The 2d Panzer Division Drive to Salonika
Entering Yugoslavia from the east on the morning of 6 April, the 2d Panzer Division (XVIII Mountain troops) advanced westward through the Strimoll Valley. It encountered little enemy resistance, but was delayed by demolitions, mine fields, and muddy roads. Nevertheless, the division divas able to reach the objective of the day, the town of Strumica. On 7 April a Yugoslav counter attack against the northern flank of the division was repelled after brief fighting. The next day the division forced its way across the mountains and overran the Greek 19th Motorized Infantry Division Units stationed south of Lake Doiran. Despite many delays along the narrow mountain roads an armored advance guard dispatched in the direction of Salonika succeeded in entering the city by the morning of 9 April. The seizure of this important objective took place without any fighting.
The Metaxas Line
The frontal attack on the Metaxas Line, undertaken by one German infantry and two reinforced mountain divisions of the XVIII Mountain Corps, met with extremely tough resistance from the Greek defenders. After a three-day struggle, during which the Germans massed artillery and dive-bombers, the Metaxas Line w as finally penetrated. The main credit for this achievement must be given to the 6th Mountain Division, which crossed a 7,000-foot snow-covered mountain range and broke through at a point that had been considered inaccessible by the Greeks. The division reached the rail line to Salonika on the evening of 7 April and entered Kherson two days later.
The other XVIII Mountain Corps units advanced step by step under great hardship. Each individual group of fortifications had to be reduced by a combination of frontal and enveloping attacks with strong tactical air support. The 5th Mountain Division together with the reinforced 125th Infantry Regiment penetrated the Strimon defenses on 7 April and, attacking along both banks of the river, cleaned out one bunker after another. After repelling several counterattacks the division reached Neon Petritsi, thus gaining access to the Rupul Gorge from the south. The 125th Infantry Regiment, which was attacking the gorge from the north, suffered such heavy casualties that it had to be withdrawn from further action after it had reached its objective. The 72d Infantry Division, which advanced from Nevrokop across the mountains, was handicapped by a shortage of pack animals, medium artillery, and mountain equipment. Nevertheless, even this division got through the Metaxas Line by the evening of 9 April, when it reached the area northeast of Seres. Some of the fortresses of the line held out for days after the German attack divisions had bypassed them and could not be reduced until heavy guns were brought up.
The Seizure of Western Thrace
The XXX Infantry Corps on the left wing progressed in a satisfactory manner and reached its designated objective. The two infantry divisions also encountered strong resistance during the first days, although both the enemy forces and fortifications were weaker here than west of the Nestos River. On the other hand, the road conditions were worse than anywhere else, often causing delay in the movement of artillery and supplies. By the evening of 8 April the 164th Infantry Division captured Xanthi, while the 50th Infantry Division advanced far beyond Komotini toward the Nestos, which both divisions reached on the next day.
Capitulation of the Greek Second Army
The seizure of Salonika by the 2d Panzer Division and the advance of the XVIII Mountain Corps across the Metaxas Line led to the collapse of Greek resistance east of the Vardar River. On 9 April the Greek Second Army capitulated unconditionally. The number of prisoners of war was not established because the Germans released all Greek soldiers after disarming them.
The Break-Through to Kozani
By the morning of 10 April the XL Panzer Corps had finished its preparations for the continuation of the offensive. A reconnaissance battalion of the SS regiment that had been sent ahead did not encounter any strong opposition until it reached the area east of Florina. Against all expectations, the enemy had left open the Monastir Gap. The Germans did not hesitate to exploit their advantage and continued the advance in the direction of Kozani.
First contact with British troops was made north of Vevi at 11:00 on 10 April. An intercepted radio message indicated that the British command was surprised by the swiftness of the SS regiment's thrust and gave orders for immediate withdrawal from the Vermion Position. The SS troops seized Vevi on 11 April, but were stopped a short distance south of that town, where strong Australian forces held the dominating heights overlooking the pass road. During the next day the SS regiment reconnoitered the enemy positions and at dusk launched a frontal attack against the pass. After heavy fighting the Germans overcame the enemy resistance and broke through the defile.
On 13 April the XL Panzer Corps commander ordered mobile elements of the 9th Panzer Division to pursue the withdrawing British forces to Kozani and cut off their communications with Verroia, situated along the southeastern foothills of the Vermion Range. The SS regiment was given the mission of cutting off the Greek First Army's route of withdrawal from Albania by driving westward and taking possession of the Kastoria area.
During the early afternoon of 13 April the 33d Panzer Regiment of the 9th Panzer Division entered Ptolemais, a town midway between Vevi and Kozani. The arrival of the German forces was greeted by heavy shelling from the hills south and southeast of the town. German reconnaissance patrols reported that the road bridge situated about 500 yards south of Ptolemais had been blown up by the British and that a ditch filled with water cut across the low ground on both sides of the road. The ditch was six feet wide and three feet deep and had soft shoulders. It constituted a perfect antitank obstacle. The patrols came under heavy fire from artillery, antitank, and machine guns emplaced on the high ground overlooking the road.
The regimental commander sent out two patrols to find a road that bypassed the ditch. Two side roads were discovered, one of which was impassable for armored vehicles since a bridge leading across the river had been demolished and steep dams dominated both banks. The other road bypassing the ditch to the west led through a swamp interspersed with several ditches but seemed passable even though there was no trace of recent vehicular traffic. Most of this road-stretch across the swamp was in plain view of the British.
The regimental commander chose the latter route for his axis of advance because it offered a possibility to envelop the enemy's dominating positions and strike his flank. The approach across the swamp was very difficult and had to be made at a walking pace under intermittent fire from British tanks and antitank guns. As soon as the first German tanks came within striking distance, they opened fire and drove off the enemy vehicles, knocking out two of them.
After having crossed the swamp the German armor deployed. Seven tanks were stuck and followed later. Speed was of the essence if the plan of attack was to succeed and the enemy was to be prevented from withdrawing. This part of the plan was complicated by the difficult terrain which rose abruptly and was broken in places. At the same time the British stepped up their artillery and antitank fire. As dusk was setting in, the German tanks assembled and suddenly emerged on the British flank with all guns ablaze. The British tanks turned about and a violent engagement developed, the result of which could not be accurately gauged because of growing darkness.
Two British self-propelled antitank guns were engaged at less than 200 yards' distance, while trying to escape. They were knocked out and a few supply trucks were captured. Some of the British tanks set up smoke screens to further reduce visibility and thus cover their withdrawal. As darkness covered the battlefield the Germans observed explosions in the distance and noticed that the enemy artillery fire was decreasing.
The plan to push on to Kozani had to be abandoned because the German tanks had expended almost all their ammunition. Some tanks had no gasoline left, while the rest had only enough for about ten miles. The British had lost their hill positions, abandoning thirty-two tanks and antitank guns as well as a number of trucks. The Germans lost 2 Mark IV, 1 Mark II, and 1 Mark I tanks in the engagement. This was the first and last tank battle that took place during the Greek campaign.
By the morning of 14 April the spearheads of the 9th Panzer Division reached Kozani. That same evening the division established a bridgehead across the Aliakmon River, but an attempt to advance beyond this point was stopped by intense enemy fire. For the next three days the 9th Panzer Division advance was stalled in front of the strongly fortified mountain positions held by the British.
The Withdrawal of the Greek First Army
The position of the Greek First Army, still fighting in Albania, was seriously jeopardized by the rapid advance of the XL Panzer Corps via Florina and by the British withdrawal to positions behind the Aliakmon. The Greek command therefore had to come to grips with the necessity of withdrawing southward from Albania. However, it was not until 13 April that the first Greek elements began to withdraw toward the Pindus Mountains. On the next day an advance detachment of the 73d Infantry Division encountered Greek troops withdrawing from Albania across the Pindus Mountains into the area west of Kastoria. Heavy fighting took place on that and the following day, especially at Kastoria Pass, where the Germans blocked the Greek withdrawal, which by then extended to the entire Albanian front, with the Italians in hesitant pursuit.
On 19 April the 1st SS Regiment which had meanwhile reached Grevena was ordered to advance southeastward in the direction of Yannina to cut off the Greeks' route of withdrawal to the south and complete their encirclement. This mission was accomplished by 20 April, following a pitched battle in the 5,000 foot high Metsovon Pass in the Pindus Mountains. Realizing the hopelessness of the situation, the Greek commander offered to surrender his army, which then consisted of fourteen divisions. After brief negotiations, which, on strict orders from Hitler, were kept secret from the Italians, the surrender was accepted with honorable terms for the defeated. In recognition of the valor with which the Greek troops had fought, their officers were permitted to retain their side arms. The soldiers were not treated as prisoners of war and were allowed to go home after the demobilization of their units.
For reasons of prestige Mussolini insisted that the Greeks also surrender to the Italians. Hostilities between the Greeks and Italians continued for two more days, and on 23 April the Greek commander signed a new surrender agreement which included the Italians.
Securing the German Rear Areas
Simultaneous with the main thrust into central Greece the Twelfth Army had to complete the pacification of eastern Macedonia, western Thrace, and the Aegean Islands. Following its capitulation the Greek Second Army was demobilizing in orderly fashion, leaving only isolated hostile forces active in these areas. The XXX Corps occupied the northeastern part of Greece, and on 19 April the 50th Infantry Division moved to Salonika, where it was to stay throughout the remainder of the campaign. The 164th Infantry Division was given the task of securing the Aegean coast and occupying the islands. On 16 and 19 April elements of the division captured Thasos and Samothraki, respectively. Limnos was seized on 25 April, and Mitilini and Khios were taken on 4 May. Even though little enemy resistance was met, this operation was not without difficulties for the ground troops. The infantry units were transported in a fleet of small boats requisitioned in various harbors along the Greek coast. Some of the boats had to travel distances of more than sixty miles. Airborne units, together with elements of the 6th Mountain Division, were employed in the seizure of some of the larger Cyclades and Sporadhes Islands.
On 13 April General Wilson decided to withdraw all British forces to the Thermopylae line. Meanwhile, General Boehme, the XVIII Mountain Corps commander had to wait until the rear elements of his divisions that were lagging behind in the Rhodope Mountains were able to close up. The advance in the direction of the Vardar was resumed as soon as the bulk of the corps had been assembled. After the Vardar crossing had been accomplished on 11 April, the 6th Mountain Division drove in the direction of Edhessa and then turned southward toward Verroia. After capturing that town the division established a bridgehead across the Aliakmon and pushed on to the high ground at the foothills of Mount Olympus. The 2d Panzer Division crossed the Aliakmon near the river bend and entered Katerini on 14 April, three hours after the 9th Panzer Division captured Kozani on the west side of the Vermion Mountains. The 5th Mountain and 72d Infantry Divisions were closing up along the 2d Panzer Division's route of advance.
A ruined castle dominated the ridge across which the coastal pass led to Platamon. During the night of 15 April, a German motorcycle battalion supported by a tank battalion attacked the ridge but were repelled by the defenders. On the next morning a special sabotage detachment, which was to outflank the Platamon position by sea in one motor and three assault boats and sail up the Pinios River to capture the bridge on the road to Larisa, had to turn back because of heavy swells.
On the morning of 16 April the 2d Panzer Division repeated its assault on the Platamon ridge. This time the Germans employed 100 tanks, two battalions of infantry, twelve 105-mm. and four 150-mm. guns as well as other artillery and technical units. They were opposed by the New Zealand 21st Battalion, four 25-pounders, and one platoon of engineers. The New Zealand commander had been told that the terrain ahead of his positions was entirely unsuitable for tank movement, and that he need expect only infantry attacks.
The German plan of attack called for simultaneous frontal and flank assaults. After a thorough artillery preparation that started at 09:00, the flank attack made good progress. The western end of the ridge was seized in hand-to-hand fighting, whereupon the German tanks began to roll up the entire position. The New Zealand battalion withdrew, crossed the Pinios River, and by dusk reached the western exit of the Pinios Gorge, suffering only light casualties.
The German tanks tried to launch a pursuit but were unable to get down the south slope of the ridge. The railway tunnel near the edge of the sea had been blown up and was impassable. One tank company attempted to edge its way along the coast but could not get through. In the end the tanks were towed over the ridge, a very time-consuming process by which only about thirty tanks were made available on the next morning.
The pursuit through the Pinios forge made little headway. The walls of the gorge rose steeply on both sides of the river. The railway tracks, along which the lead tanks made slow progress, clung to the narrow north bank of the river, while the road twisted just above the riverbed on the southern side of the gorge. The 6th Mountain Division marched across the mountains and emerged at the exit of the Pinios Gorge, only to find the bridges and ferry demolished and the railway track blocked. The tired mountain troops were met by heavy machine gun fire from the south bank of the river. By nightfall the first German tanks crossed the river, but they bogged down in a swamp while trying to bypass a road demolition.
On the morning of 18 April armored infantry crossed the river on floats, while 6th Mountain Division troops worked their way around the New Zealand battalion? which was annihilated. The struggle for the Pinios Gorge was over.
During the fighting in the Mount Olympus area the Germans were unable to move up supplies because of bad roads and traffic congestion. These difficulties were alleviated by airdrops and by shipping ammunition, rations, and gasoline by lighter along; the Aegean coast.
On 19 April the first XVIII Mountain Corps troops entered Larisa and took possession of the airfield, where the British had left their supply dumps intact. The seizure of ten truckloads of rations and fuel enabled the spearhead units to continue their drive without letup. The port of Volos, at which the British had re-embarked numerous units during the last few days, fell on 21 April; there, the Germans captured large quantities of diesel and crude oil.
Continuation of the XL Panzer Corps Drive
When it became apparent that the British had decided to offer stronger resistance along the Aliakmon than anywhere else up to that time, General Stumn1e, the XL Panzer Corps commander, decided to envelop the Aliakmon position from the west while staging holding attacks along the river front. The area around Grevena farther upstream presented a possibility for an enveloping movement. After having forced a crossing at this point, the attacker would enter terrain unfavorable to the movement of heavy vehicles because of the absence of roads and the multitude of ravines. The movement was nevertheless decided upon, since it seemed the only means of breaking the enemy resistance in this area without too much delay.
On 15 April the 5th Panzer Division, recently assigned to the corps, launched the enveloping movement north of the Aliakmon with the intention of driving southward via Kalabaka toward Lamia. As expected, the division encountered very unfavorable terrain conditions after it had crossed the Aliakmon near Grevena in the face of light resistance. Extraordinary efforts were needed to keep the heavy vehicles moving over cart roads which had been washed out by snow and rain. Not until 19 April did the division emerge from the mountains and was finally able to move at its usual speed. Lamia w as seized on the following day against minor enemy resistance. It low became apparent that too much time had been lost in crossing the mountains, since the British rear guards had meanwhile evacuated the Aliakmon and Mount Olympus lines and established themselves along the next delaying position at the Thermopylae Pass.
Before evacuating the Aliakmon position the British forces had repelled all 9th Panzer Division attacks until 17 April, when the first troops of the XVIII Mountain Corps, driving through the Pinios Gorge, entered the Plain of Thessaly, thus threatening to cut the British route of withdrawal through Larisa. During the night of 17-18 April the British succeeded in breaking contact with the German outposts and evacuating their strong positions that had remained intact. Large-scale demolitions slowed down the German pursuit on the ground, but the Luftwaffe was very active, making numerous dive-bomber attacks on the retreating British columns.
As soon as General Stumme realized that the enemy rear guard had withdrawn beyond the immediate reach of his spearheads, he issued orders giving Luftwaffe ground personnel traffic priority along the Kozani-Larisa road, so that the tactical air support units could operate -from fields that were closer to the fast-moving mobile forces.
On 19 April the 9th Panzer Division reached the Elasson area, where it was ordered to stop and assemble. Since it was not needed for the continuation of the campaign in southern Greece, the division was designated corps reserve and eventually redeployed to Germany for rehabilitation.
Regrouping of German Forces
As early as 16 April the German command had realized that the British were evacuating their troops aboard ships at Volos and Piraeus. The whole campaign had taken on the characteristics of a pursuit. For the Germans it was now primarily a question of maintaining contact with the retreating British forces and counteracting their evacuation plans. The infantry divisions were withdrawn from action because they lacked mobility. The 2d and 5th Panzer Divisions, the 1st SS Motorized Infantry Regiment, and the two mountain divisions launched the pursuit of the enemy forces. For days at a time, German flying columns were out of touch with their respective division headquarters. The distance between Larisa and Lamia, for instance, which is sixty-five miles across partly mountainous terrain, was covered in less than three days despite roadblocks, demolitions, and a number of minor engagements with British rear guards.
The supply situation was further relieved by the capture of rations and fuel stocks in the Lamia area. Even though regular supply channels failed to function because of traffic congestion and Volos, the only port in central Greece that had a satisfactory capacity, could not be cleared of mines before 27 April, the spearhead divisions were able to leave the Lamia area with an adequate supply of rations and fuel. The ammunition expenditure remained very small.
The Last British Stand at Thermopylae
To permit the evacuation of the main body of British forces, General Wilson ordered the rear guard to make a last stand at Thermopylae Pass, the gateway to Athens. On the evening of 21 April German air reconnaissance information indicated that the British defense line consisted of light field fortifications, the construction of which did not seem to have progressed beyond the initial stage. Other air reconnaissance reports showed that British troops were being evacuated from Salamis; 20 large and 15 small ships were loading troops in the port of Piraeus, 4 large and 31 small ones at Khalkis. Heavy antiaircraft fire was encountered over the ports of re-embarkation.
By 22 April a flying column of the 5th Panzer Division was attacking the Thermopylae positions that were defended by British infantry supported by well-camouflaged artillery and single tanks. The initial German probing attacks were without success. On the next day a wide enveloping movement was undertaken by 6th Mountain Division troops crossing the difficult terrain west of the British positions. This operation took place simultaneous with another outflanking maneuver performed by a tank-supported motorcycle battalion advancing via Molos. After offering strong resistance along the Molos road, the British troops abandoned the Thermopylae Pass during the night of 24-25 April.
The panzer units launching a pursuit along the road leading across the pass made slow progress because of the steep gradient and a large number of difficult hairpin bends. Occasional landslides hampered the repair of British demolitions. The railway tracks at the top of the pass were so thoroughly destroyed that repairs were estimated to take three months.
The atrocious road conditions in Greece had taken a heavy toll of German truck tires. Since no tire reserves were on hand, the vehicle attrition rate of the motorized columns rose to 35 percent after only two weeks of hostilities. The Twelfth Army supply officer therefore requested the immediate dispatch of 1,500 tires from higher headquarters.
The Seizure of the Isthmus of Corinth
An airborne operation against the Isthmus of Corinth was undertaken by two battalions of the German 2d Parachute Regiment, reinforced by one parachute engineer platoon and one parachute medical company. On 25 April more than 400 three-engine transport and tow planes as well as numerous troop and cargo-carrying gliders were transferred from the Plovdiv area in Bulgaria to the former British airfield at Larisa. H-hour for the airdrop over the objective was 07:00 on 26 April.
After leaving Larisa according to plan, the heavily loaded, slow planes took two hours for the approach flight, covering the distance at an average speed of approximately 110 miles per hour. The planes flew over the Pindus Mountains and then dropped to about 150 feet altitude above the Gulf of Corinth, heading toward their objective in column formation. They took advantage of the haze that covered the gulf and succeeded in reaching the isthmus without being observed. The pilots pulled up to 400 feet altitude, reduced speed, and dropped their loads above the designated objectives.
The first to land were the gliders, which touched ground on both sides of the isthmus. The parachute troops jumped at the same time and seized the bridge, capturing a large number of British troops.
The primary mission of seizing the bridge intact with a minimum of delay seemed to have been achieved, when an accidental hit by a British antiaircraft shell exploded the demolition charge after German engineers had succeeded in cutting the detonating cord. The bridge blew up and numerous German soldiers were buried under the debris. On the same day engineer troops constructed a temporary span next to the one that had been destroyed so that the traffic between the mainland and the Peloponnesus was interrupted for only a short time.
During the airborne operation one transport plane was forced down by squalls and crashed in the Pindus Mountains, and two gliders were wrecked while landing. Several planes suffered minor damages from antiaircraft and machine gun fire.
Had this airborne operation been executed a few days earlier in the form of a vertical envelopment, its success would have been far greater since large numbers of British troops would have been trapped and thus prevented from reaching the ports of embarkation at the southern tip of the Peloponnesus. By the time the isthmus was seized, most of the British had escaped from the Greek mainland.
The German Drive on Athens and Across the Peloponnesus
After abandoning the Thermopylae area the British rear guards withdrew to an improvised switch position south of Thebes, where they erected a last obstacle in front of Athens. The motorcycle battalion of the 2d Panzer Division, which had crossed to the island of Euboea to seize the port of Khalkis and had subsequently returned to the mainland, was given the mission of outflanking the British rear guard. The motorcycle troops encountered only slight resistance, and on the morning of 27 April the first Germans entered the Greek capital. They captured intact large quantities of POL, several thousand tons of ammunition, ten trucks loaded with sugar and ten truckloads of other rations in addition to various other equipment, weapons, and medical supplies.
The airborne seizure of the Isthmus of Corinth had been coordinated with a drive across western Greece launched on 25 April. The 1st SS Motorized Infantry Regiment, assembled at Yannina, thrust along the western foothills of the Pindus Mountains via Arta to Mesolongion and crossed over to the Peloponnesus at Patras in an effort to gain access to the isthmus from the west. Since most motorized vehicles had to be left on the mainland, the advance guard consisting of infantry and support units entrained at Patras and proceeded by railway to Corinth. Upon their arrival at 1730 on 27 April the SS forces learned that Army units advancing from Athens had already relieved the paratroops.
The SS units thereupon returned to Patras with orders to envelop the retreating British forces in the Peloponnesus from the west. The movement took place by rail and the first train arrived late on 28 April in Pirgos, where the German troops were welcomed by the mayor.
The erection of a temporary span across the Corinth Canal permitted 5th Panzer Division units to pursue the enemy forces across the Peloponnesus. Diving via Argos to Kalamai they reached the south coast on 29 April, where they were joined by SS troops arriving from Pirgos by rail. The fighting on the Peloponnesus consisted merely of small-scale engagements with isolated groups of British troops who had been unable to make ship in time. In their hasty evacuation that took place mostly at night the British used numerous small ports. On the Peloponnesus some 8,000 British and Yugoslav prisoners were captured and many Italians were liberated from Greek camps. By April 30 the last British troops had either escaped or been taken prisoner and hostilities ceased.