The 1st Sussex Engineers was a Volunteer unit of Britain's Royal Engineers raised in Eastbourne in 1890. It became the engineer component of the 44th Division of the Territorial Force, but its units saw action with Regular Army formations on the Western Front, at Salonika and in Italy during the First World War, and in North Russia and Turkey after the war ended. During the Second World War, its units were in the Battle of France and at Alamein, in Sicily, on D Day and the subsequent campaign in North West Europe, including the Rhine crossing. Detached companies fought in Tunisia, Italy, and Burma, where one was involved in the decisive Battle of Kohima and the assault crossing of the Irrawaddy. The unit continued in the postwar Territorial Army until 1967.

The Home Counties Division was an infantry division of the Territorial Force, part of the British Army, that was raised in 1908. As the name suggests, the division recruited in the Home Counties, particularly Kent, Middlesex, Surrey and Sussex.