John Butler, 15th Earl of Ormonde

John was born about 1720,^[b] probably at Kilcash Castle, his parents' habitual residence. He was the third but only surviving son of Thomas Butler of Garryricken and his wife Margaret Magennis. His father belonged to a cadet branch of the Butler Dynasty, being the grandson and heir of Richard Butler of Kilcash, who was the younger brother of James Butler, 1st Duke of Ormond. The Butlers were Old English and descended from Theobald Walter, who had been appointed Chief Butler of Ireland by King Henry II in 1177.^[9]

John's mother was the eldest daughter of William Burke, 7th Earl of Clanricarde and widow of Bryan Magennis, 5th Viscount of Iveagh. His parents were both Catholic. They had married in 1696.^[7] John had two brothers and five sisters, which are listed in his father's article.

In 1738 his father died.^[8] John inherited Kilcash and other parts of the lands of Garryricken Manor, which had been created for his grandfather Richard Butler of Kilcash shortly after 1639^[10] and had been divided between his father and his uncle John, who held Garryricken House itself. He did not inherit any title as his father held none.

In 1758, on the death of the 1st Earl of Arran, his father's second cousin, he unknowingly became de jure the 15th Earl of Ormond.^[11][12][c] It had been believed that all the titles of James Butler, 2nd Duke of Ormond became forfeit in 1715.^[13] However, in 1791, it would be found that the title of "Earl of Ormond" (and its subsidiary titles) in the peerage of Ireland had merely lain dormant and so could be successfully revived by John Butler's cousin, John Butler, 17th Earl of Ormonde.

Following the second Duke's attainder, the Ormond estate was administrated by the Forfeited Estates Commissioners. With the permission of the Parliament of Great Britain in passing the Crown Lands (Forfeited Estates) Act 1720 (7 Geo. 1. St. 1. c. 22), the estate was purchased in 1721 by the second Duke's brother, Charles, the Earl of Arran.^[14] Arran died childless in 1758. The estate passed to his unmarried sister Lady Amelia Butler, who held it for about two years. On her death in 1760, the estate was inherited by John Butler, the subject of this article.^[15][16]