However, on 11 February 1941, Barker, in common with many other officers of his rank who had fought in France and Belgium, was, at the relatively young age of 46, promoted to the acting rank of major general and became General Officer Commanding (GOC) of the 54th (East Anglian) Infantry Division, a first-line Territorial Army (TA) formation, in succession to Major General John Priestman, who was 9 years older than Barker. Despite being a first-line formation, the division contained a large number of second-line units, due to the division splitting with its second-line duplicate, the 18th Division, on a geographical basis. Barker trained his troops well in anti-invasion duties throughout the United Kingdom until, in January 1942, the division was placed on the Lower Establishment, which meant the division, in addition to receiving low priority for equipment, lost much of its artillery and other supporting units, and men were constantly being sent on overseas drafts to replace casualties, which severely hampered training. On 11 February 1942 Barker's rank of major general was made temporary, and permanent on 22 January (with seniority backdated to 17 November 1941). The drafting process continued throughout 1942 and into 1943 until, on 14 April 1943, Barker handed over the 54th Division to Major General Charles Wainwright, and was ordered to become GOC of the 49th (West Riding) Infantry Division on 30 April.