 Sir William was present in the Great Parliament of 1560 and as a great supporter of John Knox's reforms which saw the "end of popery" in Scotland as the de facto state religion.Sir John was a member of the General Assembly in 1565 which was "so obnoxious to the those of the old religion at that time".In the 1640s Alasdair Mac Colla had been sent by Montrose to suppress support for the Covenanting cause.