 On 9 April , the fall of Salonika precipitated the order for the battalion to withdraw from their positions at Katerini south to Olympus . As events unfolded elsewhere , the battalion remained in position , digging in and constructing defences until 12 April when they were ordered to withdraw behind the Mavroneri Gorge and reposition themselves on the western aspect . At this time the 5th Infantry Brigade 's orders were changed from a holding action to a delay and withdrawal . It was in the Petra Pass , alongside the 22nd Battalion , that the 28th Battalion fought its first engagement of the war . In preparation for the coming attack , the Māoris built their position , running out barbed and concertina wire and digging in while German bombers <unk> overhead . During the night they carried out patrols along the Mavroneri riverbed , but no contact was made . The following morning , the divisional cavalry , which had been carrying out a rearguard action , conducted a withdrawal through the battalion 's position , making the Māori Battalion the most forward Allied unit . As German forces were halted at Platamon by the 21st Battalion , thrusts towards Larisa once again put the battalion 's position in doubt and they were again ordered to withdraw . Meanwhile , the Anzac Corps decided to make its last stand 100 miles ( 160 km ) south at Thermopylae . 
