Other Styles of Keep

The traditional "Norman rectangular keep" was not the only style built during the Norman or later periods. The famous "Clifford's Tower" in York is Norman and quatrefoil in plan. The "Great Tower" of Raglan Castle is a neat hexagonal style and the "Great Donjon" of Bothwell was originally circular.

The Normans just happened to build more castles than anyone else and were obsessed with rectangles.

Raglan Castle
[Raglan - Monmouthshire]