John Lysaght, 1st Baron Lisle of Mountnorth, was born in 1702, the son of Nicholas Lysaght and Grace Holmes. Nicholas Lysaght was a Protestant landowner and served as a Colonel of Horse in William III’s army, notably participating in the Battle of the Boyne in 1689. He married Catherine Deane of Dublin and lived in Lisle House(now demolished), a large house in Crumlin village. Lisle Road and House is named after his Peerage – Baron Lisle.

John Lysaght received his education at Trinity College, Dublin. He entered politics and became a Member of the Irish House of Commons, representing Charleville from 1727 until 1758.

On September 18, 1758, John Lysaght was elevated to the Peerage of Ireland as Baron Lisle, of Mountnorth in the County of Cork. This title recognized his contributions and status in Irish society.

In 1725, John Lysaght married Catherine Deane of Crumlin, the third daughter and coheiress of Joseph Deane, who served as the Chief Baron of the Irish Exchequer. Catherine was the sister of Henry Boyle, 1st Earl of Shannon. John and Catherine had five children together: John Lysaght, 2nd Baron Lisle; Joseph, who married Henrietta St Leger; James, who died unmarried; Margaret, who married William Hodder; and Mary, who married Kingsmill Pennefather.

After the death of his first wife, Catherine, John Lysaght remarried in 1746 to Elizabeth Moore, the daughter of Edward Moore of Mooresfort, County Tipperary. They had additional children together.

John Lysaght’s grandfather, also named John Lysaght, had a military background as well, serving as a Cornet in Lord Inchiquin’s army during the 1641 Catholic uprising in Ireland.

John Lysaght, 1st Baron Lisle of Mountnorth, passed away in July 1781. He was succeeded in the barony by his son, John Lysaght, the 2nd Baron Lisle.