The House of Clare was a prominent Anglo-Norman noble house that ruled the Earldoms of Pembroke, Hertford and Gloucester in England and Wales throughout its history, playing a prominent role in the Norman invasion of Ireland.

The Anglo-Normans were the medieval ruling class in England following the Norman Conquest, and were primarily a combination of Normans, Frenchmen, Flemings, and Bretons who intermarried with the indigenous Anglo-Saxons and Celtic Britons. A small number of Normans had earlier befriended future Anglo-Saxon king of England, Edward the Confessor, during his exile in his mother's homeland of Normandy in northern France. When he returned to England, some of them went with him; as such, there were Normans already settled in England prior to the conquest. Edward's successor, Harold Godwinson, was defeated by Duke William the Conqueror of Normandy at the Battle of Hastings, leading to William's accession to the English throne.