 Complete the following phrase:  Time Team, in a programme first broadcast on 15 February 2009, excavated Matildas Castle in the summer of 2008. They found that visible earthworks near Radcot Bridge dated from the 17th-century English Civil War, when Parliamentary forces built them to support cannon used to bombard Royalist forces garrisoned in Radcot House. Underneath some of these earthworks were remains of a square Norman keep dating from the time of the 12th-century 