The Keep

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The Keep

For hundreds of years, Farnham Castle hid a secret. People believed the Shell Keep standing above the Bishop’s Palace was the one the Winchester Annals said Bishop Henry of Blois had built in 1138.

“In this year Bishop Henry built … the castles at Merdon, Farnham, Waltham, Downton and Taunton”.

But In 1958, archaeologists unearthed remains of an earlier tower keep buried within the larger Shell Keep.

With walls 3m thick, this first keep had been built up from ground level. A motte of compacted clay and chalk covered and protected its lower section. This unusual design may have been to protect the tower base from attack by mining or battering ram.

The height of the finished tower is unknown. The size of the base suggests a set of single rooms, one above the other, perhaps three or four storeys tall. The entrance to such early Norman towers usually stood at first-floor level with an external wooden stair.

At the bottom of the keep, a well shaft extended below ground level. Castles needed a water supply easily to hand: crucial when under siege.

The first tower may have stood for fewer than 20 years. Sometime in the middle of the 12th century, the top part of the keep disappeared. At the start of his reign, Henry II (1154–1189) ordered the destruction of many castles, including several belonging to Bishop Henry of Blois. Very probably, his order included the first keep at Farnham Castle.

The massive foundations of the original Norman tower with the well below remained until a Tudor bishop had both filled in. So the first keep disappeared for more than 400 years.

The Shell Keep

After Henry II had the first castle tower demolished, work began on a much larger structure. Records do not tell us who ordered the construction of this second keep or when building began. There is no mention of it in 12th century literature or records. But it had been completed before Bishop Peter des Roches (1205 – 1238) began his accounts in 1208.

In an unusual design, the builders constructed the walls in a protective shell around the motte’s sides, not on top. Instead of one large tower, the bishop’s soldiers now had a circle of five small ones. Filling the gap between the top of the original motte and new walls significantly increased the usable space inside.   

The builders of the Shell Keep considered its defence carefully. Evidence of a deep drawbridge pit, portcullis, meurtière (murder-hole) and arrow slits remain.  Of the Keep’s five towers, only the gatehouse still retains its original height. In the 1520s, Bishop Fox increased the gatehouse height with another level in Tudor brickwork.

In the 13th century, the keep contained only the essentials for a small garrison: soldiers’ lodgings, the well, and rooms for weapons and stores. During the next century, building activity greatly increased. Almost every one of the buildings in the Bishop’s Palace had its counterpart in the keep, from chapel to kitchen. The remains of some of these buildings are still visible.

During the Civil War, Farnham Castle’s position made it strategically important. Parliament held the Castle throughout the war, but for a few weeks in November 1642. After Colonel Sir William Waller retook the Castle at the end of that month, he ordered that one of the Keep’s towers be blown up. Further damage was done in 1648 when the House of Commons ordered:

“such effectual Course with Farnham Castle, as to put it in that Condition of Indefensibleness”

After the return of the monarchy in 1660, Bishop Morley restored the Bishop’s Palace, but left the keep in ruins. On top of the mound, the bishops planted an orchard and a garden.


Thompson, M.W. 1960. Recent excavations in the keep of Farnham Castle, Surrey. Medieval Archaeology (1960) 4, 81-94

Riall, N. The New Castles of Henry de Blois as Bishop of Winchester: The Case against Farnham, Surrey. Medieval Archaeology (2003) 47, 115-129