History of 231 Squadron:
No 231 Squadron was formed form Nos.329 and 330 Flights of the seaplane station at Felixstowe on 20 August 1918 and flew anti-submarine patrols for the remaining months of the war. On 7 July 1919 it was disbanded.
On 1 July 1940, No.231 reformed from No.416 Flight at Aldergrove as an army co-operation squadron equipped with Lysanders. In addition to taking part in excersises with the Army, it flew patrols along the border with Eire. In September 1941 conversion to Tomahawks began but a flight of Lysanders was retained until July 1943. In March 1943 the squadron moved to Yorkshire but left a detachment in Ulster until July, and in April Mustangs began to arrive. By the time No.231 joined No.128 Airfield of Second TAF on 22 July 1943, it was fully equipped with Mustangs, this type having flown the squadron's first offensive operations on 4 July. Shipping and weather reconnaissance missions, defensive patrols and ground attack sorties over northern France were flown until the squadron disbanded on 15 January 1944.
On 8 September 1944, No.231 reformed at Dorval, Canada, from No.45 Group Communications Squadron. The Group's main task was the ferrying of American and Canadian built aircraft across the Adlantic. It also administrated trans-Adlantic passenger and frieght services and No.231's Coranado flying boats opertaed between North America, West Africa and the UK, using Largs as its British terminal. Other flights were flown with landplanes, using several of the types available to No.45 Group as required. In September 1945 the squadron moved to Bermuda, where it disbanded on 15 January 1946. On 1 December 1945, a flight was formed to train Lancastarian crews at Full Sutton but its task was taken over by the station when No.231 disbanded. Although it was alloted the squadron number on 16 January 1946, training ceased on 28 March 1946.