Son of Phillip fitz William de Angulo.
Walter de Lacy gave a grant of Conmaicne to the Baron of Navan and Miles fought for him there.
He later became the lord of Sliabh Lugha in Castlemore, in what would later be called the barony of Costello.
Miles was married to a daughter of Hugh de Lacy, 1st Earl of Ulster; upon her death, she was buried at Boyle Abbey, in County Roscommon.
Miles died in 1259, and was succeeded in the title by his eldest son Hugh.