The church of St Mary de Castro is, as the name says, in Leicester castle. There has been a church on this site since the 10th century. In 1107 the church became a collegiate church and was located inside the castle's bailey. The church was expanded in 1160 with a north aisle added and an extension to the chancel.
More expansions to the castle in about 1300 included the tower and reworking of the south aisle. The spire was rebuilt in 1783 though had to be removed in 2014 after serious cracks were found in it. It is not known when, of even if, the spire will be restored.
The church is built from coursed rubble with an ashlar dressing.
