 Britain was obliged to assist Greece by the Declaration of 1939 , which stated that in the event of a threat to Greek or Romanian independence , " His Majesty 's Government would feel themselves bound at once to lend the Greek or Romanian Government ... all the support in their power . " The first British effort was the deployment of Royal Air Force ( RAF ) squadrons commanded by Air Commodore John D 'Albiac that arrived in November 1940 . With Greek government consent , British forces were dispatched to Crete on 31 October to guard Souda Bay , enabling the Greek government to redeploy the 5th Cretan Division to the mainland . 
