World War 2, Western Australia, Rottnest Island AIF Enlistment, W21809 to WX25039 ROBSON, 1942

Garrison Battalions were part of the Australian Army Reserve with the role of manning fixed defence and vulnerable points. Most personnel were Class B men, those between 48 and 55 who had seen war service before September 1939, therefore mostly WW1 veterans. However at various stages of the war, younger cohorts were drafted into the Garrison Battalions to meet home defence needs.
Before December 1941 members of the Australian Military Force (AMF - home service only) could volunteer to join the Australian Imperial Force (AIF - eligible for overseas service). However once their AMF unit was mobilised, they could not leave their unit to join the AIF. In July 1942 this prohibition was lifted and some 400 men, serving on Rottnest Island with 10 Garrison Battalion volunteered for the AIF.
10th Garrison Battalion was formed in 1940 and charged with protecting the coastal artillery on Rottnest Island until 19 Apr 1944 when they were relieved by the 5th Garrison Battalion, moving back to the mainland to take over protection for the Port of Fremantle. Later in 1944 the 10th Garrison battalion took over responsibility, albeit at a reduced level of manning, for mainland and Rottnest Island as the threat of war reduced with allied success in the islands. Sixteen Servicemen lost their lives while serving with this unit - 3 drowned, 4 in accidents and the rest of illness.