He was allocated half the estates of Walter Bourke in the parish of Turlough, five miles north of Castlebar.
These lands were confirmed to John FitzGerald in 1677 under the Acts of Settlement and Explanation of 1662 and 1665.
He first married Elizabeth Feffon, mother of Ralph Ferron, Master of Buckhounds to George II.
A granddaughter, Henrietta Fitzgerald, married Henry Grattan in 1782, by whom she had two sons and two daughters.
The estate was sold in 1991 to Mayo County Council and is now home to the Irish Museum of Country Life.