Concentric Castles

A concentric castle is a “stone castle with at least two rings of outer walls, one inside the other”. In this case, the outer wall is lower than the inner and can be defended from it. The layout was square (at Belvoir and Beaumaris) where the terrain permitted, or an irregular polygon (at Krak and Margat) where curtain walls of a spur castle followed the contours of a hill. King Edward I built numerous concentric castles in the late 1200s to early 1300s, many of which can still be seen today.

Concentric castles appeared in Europe in the 13th century, with the castles built in Wales by Edward I providing some outstanding examples, in particular Beaumaris Castle, although Beaumaris remains unfinished.

Concentric castles resemble one castle nested inside the other, thus creating an inner and outer ward. They are typically built without a central free-standing keep. Where the castle includes a particularly strong tower (donjon), such as at Krak or Margat, it projects from the inner enceinte.

Round towers couldn’t be mined as easily in a Concentric Castle. Larger Castles can house a greater number of defendants. Once inside the outer wall an attacker was still visible to defenders in a large number of towers.