 In 1938 all infantry brigades were reduced from four to three battalions and so, as a result, the 4th Battalion, Dorset Regiment was transferred to the 128th (Hampshire) Infantry Brigade.In 1939 the brigade was redesignated as 129th Infantry Brigade and the 4th Dorsets was transferred to the 130th Infantry Brigade.In the same year, the 5th Battalion, Wiltshire Regiment, formed as a 2nd Line duplicate of the 4th Wilts when the Territorials were doubled in size, also joined the brigade and the 5th Battalion, Somerset Light Infantry was transferred to 135th Infantry Brigade, part of 45th (Wessex) Infantry Division, which was formed as a 2nd Line duplicate of the 43rd (Wessex).