We are moving around in time at this point. We are now looking back at the period of 11 to 13 April 1941. You had General Mackay's group and the Central Macedonian Army moving back towards the Florina-Kozani Valley. You had the New Zealand Division and the Australians moving back towards the Aliakmon Line. By 10 April, the New Zealand Division was on Mount Olympus. By the afternoon of 12 April, a long convoy of German vehicles was seen about ten miles north of the Aliakmon river. The New Zealand Division had destroyed the "road bridge". Long range artillery fire was called in from some ten thousand yards away. The force that was blocking the enemy advance was ordered to pull back. During the night of 13 April, the New Zealand cavalry lay behind a tank ditch. Early on 14 April, the Germans started to move forward. At 10am, the rearguard was told to pull back to Katerini. By 4pm, they were back within the defenses at Mount Olympus.
At the same time, the 16th Brigade was pulling back to Servia. They had obtained donkeys from the Greek villagers. They would be used to cross the mountains. Much equipment was destroyed since it was thought to be too much for the donkeys to carry. They burned tents, buried ammunition. Even some "great coats and blankets were burnt". To increase the difficulty, they got snow at Veria during the day before the withdrawal.
General Blamey had ordered that one battalion be withdrawn immediately. The 2/3rd Battalion was pulled back to the bottom of the pass on 11 April. They provided cover to the brigade that was to move south and cross the river. By 6am on 13 April, they were able look down on the Aliakmon. This is based on the account in "Greece Crete and Syria" by Gavin Long.