Marlborough Castle

Radiocarbon dating of core samples in the early 2010s put the Mound at 2400 BC, close to the dates established for Silbury Hill. The earthwork - perhaps the "barrow of Maerla" - became the motte of the Norman castle: in 1067 William the Conqueror took control of the Marlborough area and set Roger, Bishop of Salisbury, to raise a wooden motte-and-bailey on it. Ethelric, bishop of Selsey, was imprisoned at Marlborough in 1070; the Victoria County History of Wiltshire suggests this may have been at the castle, though Richard Barber notes there is no direct reference to it.

William made the neighbouring Savernake Forest a favoured royal hunting ground, and Marlborough became a royal residence. Henry I kept Easter there in 1110, which strongly suggests the place was habitable by then.

During the Anarchy, John FitzGilbert the marshal held Marlborough for Stephen out of the fealty he owed him. Stephen besieged the castle in July 1139 and lifted the siege the following month, before the defenders capitulated, so that he could lead a campaign in another part of the country. In 1147 the fourteen-year-old future Henry II marched into Wiltshire and seized Marlborough; he was back in 1149 during talks with David I of Scotland about a northern alliance against Stephen's forces in Yorkshire.

Stone was used to strengthen the castle around 1175, and the earliest record of royal spending on it comes from 1175-6, when £43 went on building materials to create accommodation for the king.

Prince John married Isabel of Gloucester at the castle on 29 August 1189. He established a Treasury at Marlborough to support the royal mints founded by William I and William II, and the castle grew in importance as an administrative centre during his reign; he visited it 51 times. In the First Barons' War the castellan joined the rebels against John. William Marshal besieged Marlborough in 1217, John being already dead by then, and took it for the royalist cause.

From 1223 to 1224 Eleanor of Brittany, cousin of Henry III and with a better claim to the throne by primogeniture, was held here as a state prisoner, and the council proposed additional horsemen and crossbowmen for the garrison. Between 1227 and 1272 Henry III spent the enormous sum of £2,000 on the buildings, above all on the apartments and chambers and the chapel of St Nicholas.

After Henry III's death Marlborough lost favour as a royal residence, and from 1273 to 1369 it served only as a dower house. The castle and the royal borough attached to it were assigned for life in 1273 to Henry's widow, Queen Eleanor, who died in 1291; during her tenure Edmund FitzAlan, 9th Earl of Arundel, was born in the castle on 1 May 1285. In 1293 it passed to Edward I's eldest daughter, also Eleanor, who married Henry III, Count of Bar, and died in 1298 aged twenty-nine. In 1294 the castle's constable, the household knight Eustace of Hatch, was appointed to extend the dowry value of its lands to 15,000 livres tournois a year; in 1299 he was granted 90 oaks from Savernake for the renovation of the great hall and chamber.

That same year the castle was assigned to Edward I's second wife, Queen Marguerite, who died there on 14 February 1318; then to Edward II's consort, Queen Isabella, who was deprived of it between 1324 and 1327; and in 1330 to Queen Philippa, on whose death in 1369 it reverted to the Crown. Marlborough ceased to be used in 1370 and fell into disrepair, though it stayed Crown property.

The castle was a ruin by 1403. Edward VI passed the site to the Seymours, his mother's relatives, and Francis Seymour, 1st Baron Seymour of Trowbridge, who had acquired it from his elder brother William Seymour, 2nd Duke of Somerset, built a new residence there. It was replaced in 1683-4 by the "new house" for his grandson Charles Seymour, 6th Duke of Somerset, apparently to designs by John Deane, a surveyor of Reading. In the 18th century the house was the beloved residence of Isabella, Countess of Hertford, and was described by Stephen Duck, the "thresher poet".

The house then declined into a coaching inn, the Castle Inn, where the Marlborough Club of Tory gentlemen was founded in 1774 and met until 1842. The building became the nucleus of Marlborough College, founded in 1843. Excavation has identified parts of the keep and curtain wall, and the tree-covered mound within the college grounds is a scheduled monument, on private ground and closed to the public except for occasional open days organised by the local council.