He was sent by Strongbow to Ireland in 1170, and landed at Baginbun Head at the Hook Peninsula, near Waterford, where he was besieged in his entrenchments by the combined Irish and Ostmen, whom he repulsed.
Although vastly outnumbered in this battle, (his cousin Gerald of Wales gives the numbers at 3000 Irish against Le Gros's forces of about 100 including 10 Knights) he won a resounding victory which he achieved by rounding up a nearby herd of cattle which his men had foraged and driving them headlong into the oncoming enemy ranks.
The result was that about 1000 of the combined Galic and Hiberno-Norse force were either killed or captured.

He was Strongbow's second in command and had the chief share both in the capture of Waterford and in the successful assault on Dublin.
He was sent to Aquitaine to hand over Strongbow's conquests to Henry II of England, but was back in Dublin in July 1171, when he led one of the sallies from the town.
Strongbow offended him later by refusing him the marriage of his sister Basilia, widow of Robert de Quincy.
Raymond then retired to Wales and Hervey de Mountmaurice became constable in his place.

At the outbreak of a general rebellion against the earl in 1174, Raymond returned with his uncle Meiler FitzHenry, after receiving a promise of marriage with Basilia.
He brought about 450 men with him and relieved Strongbow who was under siege in Waterford.
His marriage to Basilia finally took place in Wexford directly following this encounter.
 Reinstated as constable, he secured a series of successes including the capture of Limerick city in October 1175.
Mountmaurice meanwhile obtained Raymond's recall on the ground that his power threatened the royal authority, but the constable was delayed by a fresh outbreak at Limerick, the earl's troops refusing to march without him.
On the death of Strongbow, he acted as governor until the arrival of William FitzAldelm, to whom he handed over the royal fortresses.
He was deprived of his estates near Dublin and Wexford, but the Geraldines secured the recall of FitzAldelm early in 1183, and regained their power and influence.
In 1182 he relieved his half-uncle Robert Fitz-Stephen, who was besieged in Cork.
In 1185, his first cousin Philip de Barry, son of William FitzOdo de Barry came to Ireland to assist in the recovery of some cantreds in the Kingdom of Desmond.
He was sent by Strongbow to Ireland in 1170, and landed at Baginbun Head at the Hook Peninsula, near Waterford, where he was besieged in his entrenchments by the combined Irish and Ostmen, whom he repulsed. Although vastly outnumbered in this battle, (his cousin Gerald of Wales gives the numbers at 3000 Irish against Le Gros's forces of about 100 including 10 Knights) he won a resounding victory which he achieved by rounding up a nearby herd of cattle which his men had foraged and driving them headlong into the oncoming enemy ranks. The result was that about 1000 of the combined Galic and Hiberno-Norse force were either killed or captured.
He was Strongbow's second in command and had the chief share both in the capture of Waterford and in the successful assault on Dublin. He was sent to Aquitaine to hand over Strongbow's conquests to Henry II of England, but was back in Dublin in July 1171, when he led one of the sallies from the town. Strongbow offended him later by refusing him the marriage of his sister Basilia, widow of Robert de Quincy. Raymond then retired to Wales and Hervey de Mountmaurice became constable in his place.
At the outbreak of a general rebellion against the earl in 1174, Raymond returned with his uncle Meiler FitzHenry, after receiving a promise of marriage with Basilia. He brought about 450 men with him and relieved Strongbow who was under siege in Waterford. His marriage to Basilia finally took place in Wexford directly following this encounter.  Reinstated as constable, he secured a series of successes including the capture of Limerick city in October 1175. Mountmaurice meanwhile obtained Raymond's recall on the ground that his power threatened the royal authority, but the constable was delayed by a fresh outbreak at Limerick, the earl's troops refusing to march without him. On the death of Strongbow, he acted as governor until the arrival of William FitzAldelm, to whom he handed over the royal fortresses. He was deprived of his estates near Dublin and Wexford, but the Geraldines secured the recall of FitzAldelm early in 1183, and regained their power and influence. In 1182 he relieved his half-uncle Robert Fitz-Stephen, who was besieged in Cork. In 1185, his first cousin Philip de Barry, son of William FitzOdo de Barry came to Ireland to assist in the recovery of some cantreds in the Kingdom of Desmond.
Raymond FitzGerald