The Middle East Commando began to form at Geneifa in August 1940. No.50 Middle East Commando formed up in September 1940 and became fully operational in October.

On 5 November 1940 one troop of No.50 Commando sailed for Crete as part of Assumption Force and were followed two weeks later by the remainder of the Commando arriving at Suda Bay on 26 November 1940. They came under the command of 14 Infantry Brigade whose HQ was at Canea. No.50 Commando included a detachment of 63 volunteers from Spain. A large number of these Spaniards would be among those captured in June 1941 at Crete.
No.50 Middle East Commando operations included two aborted raids on the island of Kasos, followed by Operation Abstention 25 to 28 February 1941 on the Greek island of Kastellorizo (or Castellorizo). After this they would later return to Egypt. In June 1941 Nos.50 and 52 ME Commando merged to form 'D' Bn. of Layforce for further operations in Crete.

The history of Nos.50, 51, and 52 Middle East Commandos is complex. Between September and December 1941 decisions were being made to disband them. Reformed in January 1942 as Squadrons of a new Middle East Commando operating primarily with the 8th Army in North Africa before being redsignated in April 1942 as the 1st Special Service Regiment.