In July 1753, Bowen Southwell married Lady Elizabeth Cornwallis, oldest daughter of Charles Cornwallis, 1st Earl Cornwallis, and Southwell entered the Irish House of Commons for Downpatrick in 1755, representing the constituency until 1760.
In July 1753, he married Lady Elizabeth Cornwallis, oldest daughter of Charles Cornwallis, 1st Earl Cornwallis. Southwell entered the Irish House of Commons for Downpatrick in 1755, representing the constituency until 1760. 
