Only two medieval castles survive in Berkshire, out of the original total of nine; the world-famous Windsor Castle and the much smaller and less well-known Donnington Castle, which was built on a ridge overlooking the River Lambourn, close to the confluence with the larger River Kennet, 1.5 miles north of the centre of Newbury. This fortification was a grand, crenellated manor house rather than a true castle, started in 1386 by Sir Richard Abberbury (died 1399), head of a family who had been Lords of the Manor of Donnington since 1287. The main component was an imposing, three story, twin-towered gatehouse on the east side, containing the principal living quarters, while to the west, a curtain wall enclosed an approximately rectangular courtyard flanked by six smaller towers, and within here were several lesser buildings, probably made of timber rather than stone. The castle changed ownership many times, remaining intact until the Civil War, during which (in 1646) the majority was destroyed by order of Parliament; only the gatehouse was spared.
Today, the interior of the gatehouse cannot be viewed since the entrance passageway is securely closed, but the outside of the building may be seen from all angles, and the fine quality of masonry together with the various architectural components give a good idea of the luxurious nature of the accommodation once provided by the castle. The outline of the remainder of the site is evident from partially reconstructed wall and tower foundations. The castle has a pleasant, countryside setting, partly surrounded by woodland, with good views south towards Newbury and the Lambourn valley.
As was required by law, Richard Abberbury began construction of the fortified manor after obtaining a license to crenellate, from King Richard II, however his residency of the completed building was short-lived since, following concerns about his loyalty to to the Crown, the place was sold, in 1399, to Thomas Chaucer, son of the poet Geoffrey. It later passed by marriage to the Dukes of Suffolk, before reverting to the crown in 1503. Various subsequent owners resided here over the next 140 years, and by the time of the Civil War it was in the hands of John Packer, Clerk of the Privy Seal and an ardent supporter of Parliament, though it was soon captured by Royalists, at which time its defences were improved by construction of angular earthworks on all sides, used to protect gun emplacements. Under the command of Sir John Boys, the fort held firm for over 2 years but was finally forced to surrender in 1646, soon after which all curtain walls and towers were demolished. At the conclusion of the conflict, the gatehouse was restored to John Packer. Patches of red brick in parts of the otherwise grey flint walls of the gatehouse indicate where Civil War damage was repaired. The Packers and other families held the castle until 1946, when it was acquired by the state.
Donnington Castle is reached by the B4494, north of Newbury, then by a country lane through the village of Donnington, ending at a parking area beside a farm. Access from other directions is somewhat complicated because of the major roads A339 and A34 at either side, both of which have no junction in the vicinity. The site is open all year and there is no entry fee.
A short path climbs a slope to the gatehouse entrance, passing through some grassy mounds and terraces, remnants of the earthworks that were added during the Civil War. The shape of these is not so obvious from ground level, only from above. The gatehouse is a rectangular structure of three stories, with two circular towers either side of the eastern doorway. Both originally contained spiral stairways up to the roof level, though only the southern set survives, however this, like all of the interior, is not viewable by the public due to safety concerns, and the ground floor entrance passageway is closed at both ends by iron gates. The towers and other walls are topped by crenellated parapets. Parallel, broken walls either side of the entrance are from a small, projecting, outer defensive structure. The fine medieval vaulting of the passageway roof can be seen, through the gates, together with doorways to the two towers. The castle interior was a rectangular enclosure, expanding outwards at the west side, enclosed by thick walls to second floor level, with round towers at the four corners and square towers in the middle of the north and south walls. Short lengths of the eastern wall survive to almost full height, either side of the gatehouse, each section containing one window, but the remainder of the curtain is just one or two feet high, reconstructed in order to indicate the outline of the original structure. The western gatehouse wall contains various doorways, fireplaces and other openings, all still bearing their moulded surrounds.