Bamburgh Castle is built on a basalt outcrop. The location was previously home to a fort of the native Britons and may have been the capital of the region from the realm's foundation in c.420 until 547, which is the year of the first written reference to the castle. In that year the citadel was captured by the Anglo-Saxon ruler, Ida of Bernicia (Beornice) and became Ida's seat. It was briefly retaken by the Britons from his son Hussa during the war of 590, before being relieved later the same year.
His grandson Ăelfriþ passed it on to his wife Bebba, from whom the early name Bebanburgh was derived. The Vikings destroyed the original fortification in 993.
The Normans built a new castle on the site, which forms the core of the present one. William II unsuccessfully besieged it in 1095 during a revolt supported by its owner, Robert de Mowbray, Earl of Northumbria. After Robert was captured, his wife continued the defense until coerced to surrender by the king's threat to blind her husband.
Bamburgh then became the property of the reigning English monarch. Henry II probably built the keep. As an important English outpost, the castle was the target of occasional raids from Scotland. In 1464 during the Wars of the Roses, it became the first castle in England to be defeated by artillery, at the end of a nine-month siege by Richard Neville, 16th Earl of Warwick.
The Forster family of Northumberland provided the Crown with twelve successive governors of the castle for some 400 years until the Crown granted ownership to Sir John Forster. The family retained ownership until Sir William Forster (d. 1700) was posthumously declared bankrupt, and his estates, including the castle, were sold to Lord Crew, Bishop of Durham ( husband of his sister Dorothy) under an Act of Parliament to settle the debts.
The castle deteriorated but was restored by various owners during the 18th and 19th centuries. It was finally bought by the Victorian industrialist William Armstrong.
During the Second World War, the Royal Navy corvette HMS Bamborough Castle was named after it.