Airspeed AS.10 Oxford, part eight, British users part one

During the 1930s a major expansion programme for the Royal Air Force (RAF) was directed by the British Government. This led to the issue of various operational requirements issued by the Air Ministry, being one of those the Operational Requirement 42 (OR 42) which sought for an advanced training aircraft to be used by the aircrews destined to serve on bombers. Given the RAF's situation, which was migrating from biplane aircraft to monoplanes, as they were more technically more capable and demanded different flying characteristics, a suitable trainer was needed to match this change. The Avro Anson was considered for this role, however, on second thoughts, a more difficult aircraft to fly was seen as a better option. Therefore, on 10th July 1936 the Specification T.23/26 was issued to Airspeed for the development of a twin-engined training aircraft which would meet the specification of the OR 42.
The Oxford was developed to meet the requirements of the T.23/26 and, as such, it was based on Airspeed's existing commercial 8-seater airliner, the AS.6 Envoy which was designed by Hessell Tiltman. Seven Envoys were already converted by the South African Air Force which could be completed in short time by adding bomb racks and a dorsal machine gun placed within a turret designed by Armstrong-Whitworth. The work on this "convertible Envoy" reported many benefits on their subsequent work on the Oxford. The Air Ministry approved the project placing an initial order of the type in 1937.
It was decided for a large initial batch of 136 aircraft, as it allowed for a more economical flow-line production at Airspeed factory in Portsmouth. On 19th June 1937 the first prototype flew and, initially, two variants were projected, Mk.I which was conceived as a general-purpose training aircraft equipped with a dorsal turret and the Mk.II which lacked the turret but was fitted with dual controls. As further large contracts were placed (100 Mk.Is and 100 Mk.IIs) it was decided that De Havilland would also build them at Hatfield. Other companies like Percival or The Standard Motor Company also manufactured the aircraft. In fact, regarding the Mk.I 3.492 machine were completed at Airspeed's Portsmouth factory between 1937 and April 1945, 300 of them were completed at Airspeed secondary factory in Christchurch, Hampshire between April 1941 and February 1943, 961 were completed by De Havilland at Hatfield, Hertfordshire between February 1939 and January 1941, 774 were completed by Percival at their factory in Luton, Bedfordshire between 1942 and April 1944 and 750 were completed by The Standard Motor Company in Coventry at Warwickshire between February 1941 and July 1943.
Regarding the Mk.II variant, the numbers are as follows:
Of a total of 2028 aircraft 726 of them were manufactured at Airspeed in Portsmouth between 1939 and 1942, 250 at Airspeed in Christchurch between 1941 and 1942, 552 by De Havilland at Hatfield between 1939 and 1941 and 575 were completed by Percival between November 1939 and 1942 in Luton.
By the end of production in April 1945, a total of 8.751 Oxfords were completed.

Sources:
1. https://en.wikipedia.org/wiki/Airspeed_Oxford
2. https://www.valka.cz/Airspeed-Oxford-Mk-I-t6612
3. https://www.valka.cz/Airspeed-Oxford-Mk-II-t47500