The development team tried to match the lower weight of a cruiser tank, allowing the suspension and transmission parts of the A10 heavy cruiser to be used, with the greater armour of an infantry tank, working to a specification for a 60 mm (2.4 in) armour basis (the same as the A.11).
As a private design by Vickers-Armstrongs, it did not receive a General Staff 'A' designation it was submitted to the War Office on 10 February 1938. The Valentine started as a proposal based on Vickers' experience with the A9 and A10 specification cruiser tanks and the A11 (Infantry Tank Mk I). The 'most prosaic' explanation according to David Fletcher is that it was just an in-house codeword of Vickers with no other significance. Another version says that Valentine is an acronym for Vickers-Armstrongs Limited Elswick & (Newcastle-upon) Tyne. White notes that 'incidentally' Valentine was the middle name of Sir John Carden, the man who was responsible for many tank designs including that of the Valentine's predecessors, the A10 and A11. According to the most popular one, the design was presented to the War Office on St Valentine's Day, 14 February 1940, although some sources say that the design was submitted on Valentine's Day 1938 or 10 February 1938.
There are several proposed explanations for the name Valentine.
