 In the first year of the Second Anglo-Dutch War, at the Battle of Lowestoft on 13 June 1665, the Dutch suffered the worst defeat in the history the Dutch Republic's navy.At least sixteen ships lost, and one-third of its personnel captured or killed; Van Wassenaer was among the dead.On his return to the republic, De Ruyter learned that Van Wassenaer had been killed at Lowestoft.