Lewes is a rare example of a castle that has two mottes associated with one bailey (Lincoln Castle is another). It was built by William de Warenne, around 1069-70, and became the main seat for his family. In 1088, William was made Earl of Surrey, and the title continued until 1347, with the death of the last of the line, John de Warenne, the 8th Earl.

The shell keep was built in the early 12th century, and two semi-octagonal towers were added to it in the 13th century. In the 14th century a magnificent barbican was added to what had previously been a poorly defended main gate. This barbican and much of the shell keep are still standing and you can climb to the top of both. Admission to the castle also includes entrance to the Barbican House museum.