Richard Mór de Burgh, born towards the end of the year in 1193, was the eldest son and heir of William de Burgh and his wife who was the daughter of Domnall Mór Ua Briain, King of Thomond. De Burgh's principal estate was in the barony of Loughrea where he built a castle in 1236 and a town was founded. He also founded Galway town and Ballinasloe. The islands on Lough Mask and Lough Orben were also part of his demesne. From the death of his father in 1206 to 1214, Richard was a ward of the crown of England until he received his inheritance. In 1215 he briefly served in the household of his uncle Hubert de Burgh, Earl of Kent. In 1223 and again in 1225 he was appointed seneschal of Munster and keeper of Limerick castle.
In 1224, Richard claimed Connacht, which had been granted to his father but never, in fact, conquered by him. He asserted that the grant to Cathal Crobdearg Ua Conchobair, the Gaelic king, after his father's death had been on condition of faithful service, and that his son Aedh mac Cathal Crobdearg Ua Conchobair, who succeeded Cathal that year, had forfeited it. He had the favour of the justiciar of England, Hubert de Burgh, and was awarded Connacht in May 1227. Having been given custody of the counties of Cork and Waterford and all the crown lands of Decies and Desmond, he was appointed Justiciar of Ireland from 1228 to 1232. When in 1232 Hubert de Burgh fell from grace, Richard was able to distance himself and avoid being campaigned against by the King of England, Henry III. It was only in 1235 when he summoned the whole feudal host of the English lords and magnates to aid him that he expelled Felim mac Cathal Crobderg Ua Conchobair, the Gaelic king, from Connacht. He and his lieutenants received great shares of land, while Felim was obliged to do homage and was allowed only to keep five cantredsRoscommon from the Crown. Richard de Burgh held the remaining 25 cantreds of Connacht in chief of the crown of England. De Burgh took the title of "Lord of Connacht".
Wife and children
Before 21 April 1225, he married Egidia de Lacy, daughter of Walter de Lacy, and Margaret de Braose. With this alliance he acquired the cantred of Eóghanacht Caisil with the castle of Ardmayle in Tipperary. Richard de Burgh had three sons and four daughters by his wife, Egidia de Lacy:
