IX Corps
Disbanded in 1919 after the First World War ended, IX Corps was reformed during the Second World War in the United Kingdom in April 1941, under the command of Lieutenant General Ridley P. Pakenham-Walsh. The 59th (Staffordshire) Infantry Division and the Durham and North Riding County Division transferred to IX Corps from X Corps on 9 April 1941, which suggests this is the date the IX Corps became effective. The Northumberland County Division joined IX Corps the following day.