Owen’s father, Owen Wynne I, came to Ireland from Wales in 1658 after acquiring extensive lands around Lurganboy during the Cromwellian land settlement. He married Catherine Hamilton who had been firstly married to Captain James Hamilton, son and heir of Sir Frederick Hamilton. Owen and Catherine had four sons and three daughters. Their third son, Owen II, was born in Lurganboy Lodge. He was educated at Trinity College Dublin and studied for the Bar. He subsequently enlisted in the army and in 1689 was a captain in the earl of Roscommon’s regiment of foot. The following year he fought with the Williamite forces at the Battle of the Boyne. Owen entered politics and held the position of MP for Carrick-on-Shannon from 1692 to 1695. However, he left Ireland for Flanders with his brother James’ Wynne’s Dragoons in 1694. During the War of the Spanish Succession (1701-1714), he was appointed colonel of the 23rd Regiment of Foot and later attained the rank of major-general. He became a very wealthy man and bought land in Co. Cavan for £15,000 in 1720. Shortly afterwards he acquired the family’s Sligo estates, comprising 14,500 acres and built Hazelwood House on the shores of Lough Gill. In 1727 he was promoted to lieutenant-general and appointed commander-in-chief of the army in Ireland. Owen married a daughter of Robert Miller from Milford in Co. Mayo, but had no children. He left his estates in Leitrim and Sligo to his nephew, Owen Wynne III.