 The war ended on 5 April 1654, with the signing of the Treaty of Westminster (ratified by the States General on 8 May), but the commercial rivalry was not resolved, the English having failed to replace the Dutch as the world's dominant trade nation.The treaty contained a secret annex, the Act of Seclusion, forbidding the infant Prince William III of Orange from becoming stadtholder of the province of Holland, which would prove to be a future cause of discontent.In 1653 the Dutch had started a major naval expansion programme, building sixty larger vessels, partly closing the qualitative gap with the English fleet.