 On the day of his creation, Sir Alexander was, with a gallant little garrison, defending Tantallon Castle against Oliver Cromwell who had laid siege to it.Following twelve days and a "battering with grate canon" the defenders were compelled to surrender, but only after quarter had been granted to them in recognition of their bravery.In 1668 Lord Kingston was appointed, by the King, commander of the Haddingtonshire Militia.