Background
Montgomery was the son of Henry Montgomery, 3rd Earl of Mount Alexander, by the Honourable Mary Street Lawrence, daughter of William Street Lawrence, 12th Baron Howth.
Montgomery was the son of Henry Montgomery, 3rd Earl of Mount Alexander, by the Honourable Mary Street Lawrence, daughter of William Street Lawrence, 12th Baron Howth.
He was returned to the Irish House of Commons for Antrim Borough in 1703, a seat he held until 1713. He entered the Irish House of Lords on the death of his father in 1731. Lord Mount Alexander married Elinor Barnewall, daughter of Sir Patrick Barnewall, 3rd Baronet, of Crickstown, in 1703.
The Countess of Mount Alexander died in December 1746.