The Mediterranean Expeditionary Force (MEF) was part of the British Army during World War I, that commanded all Allied forces at Gallipoli and Salonika. This included the initial naval operation to force the straits of the Dardanelles. Its headquarters was formed in March 1915. The MEF was originally commanded by General Sir Ian Hamilton until he was dismissed due to the failure of the 29th Division at Gallipoli. Command briefly passed to General William Birdwood, commander of the Australian and New Zealand Army Corps, but for the duration of the Gallipoli campaign it was General Sir Charles Monro who led the MEF.