This series deals with Allied operations in the Mediterranean Theatre, and covers the campaigns in North Africa, Sicily and Italy; military aid to the Balkans and Greece; and military government of occupied territories. The papers are those of the combined Anglo-American forces of Allied Force Headquarters (AFHQ), activated in September 1942. Records of units which were not integrated were for the most part treated separately after the War, and are not included. American records were returned to the United States.

Also included are the records of the various Commissions and Boards controlled by AFHQ and of Formation Headquarters immediately under its command. This includes some of the Mediterranean Allied Air Forces, as well as Headquarters Allied Armies Italy (15 Army Group), Allied Military Headquarters (Balkans), Land Forces (Greece), Military Liaison Headquarters (Albania) and (Yugoslavia) and Headquarters Allied Commission (Italy).

The bulk of the collection, however, is made up of records of the Supreme Allied Commander's Secretariat, the branches G 1 (Adjutant- General, responsible for the overall records management of combined forces and those including many extraneous as well as its own records), G 2 (Intelligence), G 3 (Operations), G 4 (Quartermaster-General), and G 5 (Military Government and Civil Affairs), and the Psychological Warfare branch.