The 139th Brigade was an infantry brigade of the British Army that saw active service in the First World War with the 46th Division. Later designated the 139th Infantry Brigade, the brigade also saw service with the 46th Infantry Division in the Second World War.

The 3rd Battalion, London Regiment was a volunteer unit of the British Army under various titles from 1860 to 1961. Originally raised from railwaymen, the battalion sent a detachment to the Second Boer War and several battalions fought in World War I. Shortly before World War II, it became a searchlight unit and defended the UK during the Blitz, remaining in the air defence role in the postwar Territorial Army.