Although originally ordered as a Black Prince Class, 74 gun, Third Rate ship of the line, to be built for the Royal Navy by the Honourable East India Company at their shipyard at Bombay, HMS Wellesley ended up being built to the design of the Vengeur Class.
The Black Prince Class were built to a reduced version of the design of the Danish ship Christian VII of 80 guns, which was handed over by the Danes to the Royal Navy as part of the settlement following the Bombardment of Copenhagen. The design of the Christian VII was found to be superior to the 80 gun ships captured from the French, in that her hull was much stiffer, making her a better sailer. The design was ordered to be copied, line for line in the form of HMS Indus, launched at Portsmouth Royal Dockyard in 1824 and in a reduced form, for the four ships of the Black Prince Class, of which two were built in Kent.
HMS Wellesley was originally intended to be a fifth member of the class, but the ship bringing the plans to India was taken and destroyed by the Americans during the war of 1812. The Bombay shipyard had recently completed HMS Cornwallis, so still had the plans and more importantly, the moulds for the Vengeur Class, so to save time, HMS Wellesley was built to that design instead.