[3]: 119 The castle was originally a basic, 5-storied Irish tower house which was built c. 1480 – c. 1490, probably by Toirdhealbhach Donn Ó Briain of the O'Brien family, one of the last of the High Kings of Ireland and a direct descendant of Brian Boru.

[4] In 1543, Turlogh Donn's son, Murrough surrendered his title of King to Henry VIII and was created in 1st Earl of Thomond and Baron Inchiquin.

Her father was Sir Torlach Rua MacMahon, Lord of Clonderlaw and her mother was Lady Mary O'Brien, daughter of the third Earl of Thomond.

Her first husband, Daniel O'Neylan (also sometimes written O'Neillan or Neylan) of Dysert O'Dea Castle in north Clare died young and upon his death, she gained control of his substantial estate and a £1,000 fortune.

Reportedly, immediately after her husband's death, the widow, realizing that the punishment for his rebellion against the English would be the forfeiture of their property, drove to Limerick and offered to marry any Cromwellian officer who would take her hand.

General Ludlow, who commanded the English Parliament forces at Inchicronan subsequently conducted counter-insurgency operations in the Burren, making his well-known statement about the area's barrenness.

However, he later ran into financial difficulty and, as a result, the estate which he had married into at Leamaneh, which he under law now owned through his wife, was mortgaged to repay his debts.

Máire Rua's son, Donagh or Donough (after 1686 Sir Donat) found the tower and manor damaged but stayed there until 1684/1685, when he moved the family seat from Leamaneh to the much larger Dromoland Castle in Newmarket-on-Fergus, south of Ennis.

[4] Although Máire Rua's children from her first marriage to Daniel O'Neylan (or O'Neillan) were raised Catholic, Sir Donagh/Donat was brought up as a Protestant and eventually became the "richest commoner in Ireland."