4th Infantry Brigade and Headquarters North East (The Black Rats), previously known as 4th Mechanized Brigade (The Black Rats) is a brigade formation of the British Army, currently based in Catterick, North Yorkshire as part of 1st (United Kingdom) Division. The brigade, now known as the 'Black Rats', was formed in 1939 and fought in the Second World War in the Western Desert Campaign in North Africa. The Black Rats were subsequently involved in the invasion of Sicily and fighting in Italy before taking part in the Battle of Normandy and the advance through Belgium, Holland and into Germany.