Keep

The White Tower in London provides a concrete example from Norman England, c1066–c1100. It is the great stone keep at the heart of the Tower of London, rather than the whole castle complex. In William the Conqueror's time it was known as the Great Tower.

At Berkhamsted, Edgar, Edwin and Morcar submitted to William. They swore oaths of loyalty and gave him hostages as guarantees that they would keep their promises. Submission meant accepting William’s authority; the hostages provided an additional safeguard beyond spoken promises.

One reconstruction places the mound near the later site of John of Gaunt’s hall or beneath the Norman keep, with the later inner court occupying the early bailey. However, another interpretation is that the stone keep itself was the first phase of Geoffrey de Clinton’s castle in the 1120s. Kenilworth’s earliest layout should therefore be understood as uncertain, rather than presented as a definite timber castle followed by a stone replacement.

The motte was a raised mound with a wooden tower, or keep, on top. Its height gave defenders a better view of approaching attackers and made the strongpoint harder to reach.