Career
Erne was a major landowner in County Fermanagh. He represented Lifford in the Irish House of Commons from 1727 until 1768, when he was raised to the Peerage of Ireland as Baron Erne, of Crom Castle in the County of Fermanagh. Up to 1729 Alexander Montgomery shared the parliamentary patronage of Lifford, County Donegal with the Creighton family, the Earls of Erne.
There is an agreement in the Erne papers (held in the Northern Ireland Public Records Office) dated 1727 between Alexander Montgomery and General David Creighton about the sharing of Lifford Corporation and its representation in the Irish House of Commons, to which it sent two M.P.s.
One of the articles of agreement was that, if Montgomery should die without a son, then his interest should pass to the Creightons. Montgomery was elected as an Member of Parliament General David Creighton died in 1728 so the Lifford seat was filled by Thomas Montgomery, the nephew of Alexander.
On the death of Thomas Montgomery in 1760, full control of the Lifford seats passed to Abraham Creighton.
