He was born in Ireland in 1194, the son of
Gerald FitzMaurice, 1st Lord of Offaly and
Eve de Bermingham (died between June 1223/December 1226). He succeeded to the title of Lord of Offaly on 15 January 1204, and was invested as a knight in July 1217, at the age of 33. In 1224 he founded
South Abbey, Youghal, the proto-
friary of the Irish
Province of the Observant
Franciscans, dedicated to St. Nicholas. Maurice was summoned to London to accompany King
Henry III of England to
Poitou and
Gascony in October 1229. He was appointed Justiciar of Ireland in September 1232 and held the post until 1245. His reputation was marred by rumours that he had contrived the death of
Richard Marshal, 3rd Earl of Pembroke in 1234. FitzGerald met Marshal at the
Battle of the Curragh on 1 April, where Marshal was wounded and died shortly after. It was rumoured that Marshal had been betrayed. FitzGerald then proceeded to London, where he took an oath before Henry III, that he innocent of any participation in Marshal's death. He later founded the Dominican Abbey at Sligo, to house a community of monks to say prayers for Earl Marshal's soul. In February 1235, the King criticised him for his proceedings in office, and described him as "little pleasant, nay, beyond measure harsh in executing the King's mandates". In 1245, Maurice was dismissed from his post as Justiciar as a result of tardiness in sending the King assistance in the latter's military campaigns in
Wales. His successor was
John FitzGeoffrey. That same year he laid the foundations for
Sligo Castle. In 1250, he held both the office of Member of the Council of Ireland, and Commissioner of the Treasury. He also founded the
Franciscan Friary at Youghal; hence his nickname of
an Brathair, which is Irish for
The Friar. He was at the English royal court in January 1252, and received an urgent summons from King Henry in January 1254. ==Marriage and issue==