Earl of Lanesborough was a title in the Peerage of Ireland. It was created in 1756 for Humphrey Butler, 2nd Viscount Lanesborough. The Butler family descended from Theophilus Butler, who represented County Cavan and Belturbet in the Irish House of Commons. In 1715 he was raised to the Peerage of Ireland as Baron Newtown-Butler, of the County of Fermanagh, with remainder to the heirs male of his father. He was succeeded according to the special remainder by his brother, Brinsley, the second Baron. He had previously represented Kells and Belturbet in the Irish Parliament. In 1728 he was created Viscount Lanesborough in the Peerage of Ireland. He was succeeded by his son, Humphrey, the aforementioned second Viscount, who was elevated to an earldom in 1756. The first Earl was succeeded by his son, Brinsley, the second Earl. He represented County Cavan in the Irish House of Commons. His grandson, the fifth Earl, sat in the British House of Lords as an Irish representative peer from 1849 to 1866. The latter was succeeded by his nephew, the sixth Earl. He served as Lord-Lieutenant of Cavan from 1876 to 1900 and was an Irish Representative Peer from 1870 to 1905. He was succeeded by his son, the seventh Earl. He was an Irish Representative Peer from 1913 to 1929. On his death the titles passed to his younger brother, the eighth Earl. The titles became extinct on the death of the latter's eldest son, the ninth Earl, in December 1998.
The Honourable John Butler, younger son of the first Viscount, was a member of the Irish Parliament for Newcastle between 1743 and 1783.
The Butler family trace their lineage back to county of Huntingdon and George Butler who resided at Fen Drayton in 1575 who had six sons one son Stephen Butler who settled in Belturbet County of Cavan in Ireland.Stephen Butler's son Theophilus Butler was created Baron of Newtown-Butler and began family descent.
| Crest: | 1st: A Wyvern with wings elevated and tail nowed Or the dexter paw supporting a Shield Argent thereon a Bend Gules charged with three Martlets Gold (Danvers); 2nd: A Demi Cockatrice couped Vert wings elevated Argent combed beaked wattled and ducally gorged Or (Butler) |
| Coronet: | A Coronet of an Earl |
| Escutcheon: | Quarterly: 1st and 4th, Gules a Chevron wavy between three Mullets of six points radiant Or pierced Azure (Danvers); 2nd and 3rd, Argent three Covered Cups in bend between two Bendlets engrailed Sable (Butler) |
| Supporters: | On the dexter side a Cockatrice Vert with wings elevated Argent combed beaked wattled and ducally gorged Or, and on the sinister side a Wyvern Vert gorged with a Plain Collar and chained Or |
| Motto: | Liberte Tout Entiere (Liberty entire) |