Faringdon Castle was a Norman castle standing just outside the market town of Faringdon in the English county of Berkshire (now Oxfordshire), some 17 km to the north-east of Swindon (). This castle was built on the site of an Iron Age hillfort known as Faringdon Clump by Robert, Earl of Gloucester in 1144 in support of Matilda in the Anarchy. The Gesta Stephani, a contemporary chronicle, recorded the founding of the castle and the earl's activities, noting that it was "strongly fortified by a rampart and stockade, and putting in it a garrison that was the flower of his whole army he valorously restrained the wonted attacks from the king's soldiers, who had been coming out of Oxford and other castles round about to harass his own side". A few weeks after Faringdon Castle was built it was be