18 April 1941. Grevena, Greece.
The stand by the Greek Cavalry Division at the Klisoura pass, like that of the 20th Division at Vlasti, and the 12th Division at Siatista, would perhaps in time be remembered as one of the great achievements of Greek arms. Holding off the Germans with their superior numbers and equipment was a matter of bayonet and determination. By 16 April the Germans had been held up long enough for the main elements of the Western Macedonian Army to withdraw from Albania. The remnants Cavalry Division had finally given up Kastoria and withdrawn past Vlasti, from where the 20th Division also withdrew. At Siatista, the Greek 12th Division pulled back from the pass that they had so resolutely defended. A squadron of tanks from 3rd Hussars and other British anti-tank units supported the Greek Divisions’ movement to behind the Venetikos River.
The rest of the 3rd Hussars, along with a battalion of Australians had been covering the river crossings to allow the weary Greek troops time to get across, while other Greek units (1st, 9th and 10th Divisions) dug in and prepared to meet the next phase of the German invasion. The arrival of the forward German units at Grevena, opposed by the Australians and 3rd Hussars, on 17 April, put the entire Aliakmon-Venetikos Line under attack.
The assaults on both the 6th Australian Division and the 2nd New Zealand Division had been resisted stoutly, but their positions were becoming untenable as the German Mountain Division had been working their way around the defenders’ positions. It was becoming clear to both General Blamey and General Freyberg that holding their current positions was becoming impossible. The Battalions in direct contact with the Germans had been taking heavy casualties, it wouldn’t take much for the line to break completely.
With the planning to move back to the Thermopylae well advanced, the order had gone out for the Australian 6th Division to begin its withdrawal that night. Brigadier Savage’s 17th Brigade and 1st Armoured Brigade would cover their withdrawal. The Division’s transport would move as close as possible to the front line, to allow the Australians to have most of the night on their lorries to get to their new positions. The Australians would be followed the following night with the New Zealanders passing through Larissa and Lamia to their new positions. The withdrawal of the RAF from their air fields to two closer to Athens was necessary at any rate, the losses of aircraft on the ground had been particularly heavy. The lessons learned from the retreat to Dunkirk, to leave nothing of value for the enemy, were being applied rigorously. Rations were being passed to the Greek civilians, petrol, oil and lubricants were moved or destroyed in place, as were stocks of ammunition. The Royal Engineers were also working feverishly to prepare as many demolitions as possible.
For General Papagos, the decision for the British to withdraw to the Thermopylae passes left the Greek positions vulnerable to a German movement across the Pindus Mountain passes. So, he ordered the Cretan 5th Division to the pass at Metsovon to protect the road through Ioannina which was now the main supply line for his whole army. General Papagos also asked the Greek Navy to relocate the men who had been called up for service in the army, and still undergoing training, to Crete. When this came to the attention of General Wavell, he asked that these men should be brought to Egypt to complete their training and have their equipment needs met. Papagos and the Greek King agreed, looking to rebuild an army that might be part of the liberation of the Greek islands, and perhaps one day, the mainland itself. Over the next week just under 50000 men were shipped to Egypt and Palestine. The Royal Navy also started lifting non-essential British troops, as well as elements of the RAF who were redeploying to Crete, from Greece at the same time.