Colonel Alexander Montgomery was M.P. for County Monaghan from 1713 to 1722.
He was High Sheriff of County Monaghan in 1718. He was a captain of dragoons in the Monaghan Militia in 1708.
His father was Major John Montgomery of Crogan, County Donegal. He joined the British Army and was appointed a captain of the Inniskilling Dragoons in 1689, a major in 1704 and a lieutenant-colonel in 1706.
He married Elizabeth Cole, the daughter of Thomas Cole, Esquire of Mount Florence, County Fermanagh. Elizabeth's dowry was the Ballyleck estate in County Monaghan, where Colonel Montgomery then took up residence, thus founding the line of Montgomery of Ballyleck.
They had four sons and one daughter, viz.
Colonel Montgomery died on the 15th March 1722 and his will dated 28th August 1721 was proved on 6th July 1722.
The Montgomery Manuscripts written in 1704 (http://books.google.co.uk/books?id=MyQ2OPhI_nIC&pg=PA392&dq=Major+%22John+Montgomery%22+Crogan&cd=4#v=onepage&q=&f=false) states
"Alexander Montgomery is the second grandson of Reverend Alexander Montgomery, Prebendary of Doe, County Donegal. He was a Captain in ye 3rd regiment, and now in 1704 a major because it was not reduced: married Captain Coles (in ye County of Monaghan) his daughter and heiress, and now lives within two miles of Monaghan town, and hath a son, this gentleman hath a good Estate, and is a thriving man and a great tenant to ye present Duke of Ormond".