Born in Belfast, William Johnston was the son of Rt.
Thus, like many of his contemporaries, Sir William's family was involved in Ulster's thriving linen trade.
In Belfast's civic life, Sir William was High Sheriff and Lord Mayor of Belfast from May 1949 to May 1951, and an ex officio member of the Senate of Northern Ireland, the upper house of the Stormont Parliament.
Dr. William Patterson, of Cooke Church, Toronto, Ontario, Canada.
The couple had one son and lived at Wellington Park, Malone Road, Belfast, where Sir William died in 1951.