The 52nd (Lowland) Division, which had seen numerous changes in composition during the inter war period, was mobilised, along with the rest of the Territorial Army (previously the Territorial Force, reformed in 1920 and soon renamed the TA), in late August 1939, due to the worsening situation in Europe at the time. The Second World War began on 3 September 1939, after both Britain and France declared war on Germany after the latter's invasion of Poland and the 52nd, based in Scotland under the command of Major-General James Drew,[was serving in Scottish Command, alongside its second line duplicate unit, the 15th (Scottish) Infantry Division. The division was briefly deployed to France, following the Dunkirk evacuation, as part of the Second British Expeditionary Force (2BEF) to cover the withdrawal of Allied forces near Cherbourg during Operation Ariel. The division returned to the United Kingdom and, like most of the rest of the British Army after Dunkirk, began training to repel an expected German invasion, which never occurred. From May 1942 until June 1944, the 52nd was trained in a mountain warfare capacity, originally for a proposed invasion of Norway. However, the division was never employed in this role. Following June 1944, the 52nd Division was reorganised and trained in air landing operations. As part of this new role, the division was transferred to the First Allied Airborne Army. By this time, the 52nd Division was under the command of Major-General Edmund Hakewill-Smith. The division would never be utilised in either of the roles it had trained for, and was transferred to Belgium via sea landing in Ostend. The 157th Infantry Brigade landed first at the end of the first week of October, and the rest of the division arrived over the course of the following fortnight.[On 15 October, the 157th Brigade was, temporarily, attached to the 3rd Canadian Infantry Division and relieved the Canadian units in the bridgehead over the Leopold Canal. From 23 October until December, the 52nd (Lowland) Division was assigned to the Canadian First Army, serving first under II Canadian Corps and then British I Corps. The division's first operation would be to aid in opening the vital Belgian port of Antwerp, in the Battle of the Scheldt. Ironically, the first operation of the division would not be in mountainous terrain or being deployed by air, but fighting below sea level on the flooded polders around the Scheldt Estuary of Belgium and the Netherlands. Operation Vitality and Operation Infatuate were aimed at capturing South Beveland and the island of Walcheren to open the mouth of the Scheldt Estuary. This would enable the Allies to use the port of Antwerp as a supply route for the troops in North-West Europe. It was in this vital operation that the 52nd Division was to fight its first battle with brilliant success that earned them high praise. During the battle, the division was given command "of all the military operations" on Walcheren. This included command of the 4th Commando Brigade, after it had landed on the island, and No. 4 Commando during the assault on Flushing. Following the battle the division would remain on Walcheren until November, when it was relieved by the 4th Canadian Armoured Division. On 5 December, the division was transferred to XXX Corps of the British Second Army. During the month, the 157th Infantry Brigade was temporarily attached to the 43rd (Wessex) Infantry Division for several days. In January 1945, the 52nd Division, now serving under XII Corps, participated in Operation Blackcock, the clearing of the Roer Triangle between the rivers Meuse and Roer. During the operation, the 155th Infantry Brigade was attached to the 7th Armoured Division.