Lord Aylmer, Baron of Balrath, in the County of Meath, is a title in the Peerage of Ireland. It was created in 1718 for the naval commander Matthew Aylmer, the second son of Sir Christopher Aylmer, 1st Baronet, of Balrath (see below). Lord Aylmer's son, the second Baron, represented Rye in the House of Commons. The latter's grandson, the fourth Baron, succeeded his kinsman as seventh Baronet, of Balrath, in 1776. The titles remain united. He was succeeded in both titles by his son, the fifth Baron. He was a general in the Army and served as Governor General of Canada from 1830 to 1835. Lord Aylmer assumed by Royal licence the additional surname of Whitworth in 1825 on the death of his uncle Charles Whitworth, 1st Earl Whitworth. On his death the titles passed to his younger brother, the sixth Baron. He was an admiral in the Royal Navy.
He was succeeded by his second cousin, Udolphus Aylmer, the seventh Baron, born June 10, 1814 and living in Canada. He was the son of John Athalmer Aylmer, eldest son of Admiral John Aylmer, son of Reverend the Hon. John Aylmer, fourth son of the second Baron. His claim to the titles was not allowed until 1860, however. His son Matthew Aylmer, the eighth Baron, was a major-general in the Canadian Army. His third son, the eleventh Baron, was succeeded by his third cousin, the twelfth Baron. He was the great-grandson of Major-General Harry Aylmer, second son of the aforementioned Admiral John Aylmer. On his death in 1982 the title passed to his second cousin, the thirteenth Baron. He was the grandson of Frederick Arthur Aylmer, second son of Major-General Harry Aylmer. As of 2014[update] the titles are held by his son, the fourteenth Baron.