Medieval chapel; schoolroom.


This simple L-shaped building began life as the church for the small community which built up around Castle Rushen and later became the Island's capital for over 600 years. An arcade of three arches along its south wall was required by religious ceremonies; elsewhere on the Island only St German's Cathedral at Peel Castle boasts a similar architectural feature from this time. Early in its history meetings of Tynwald at Castle Rushen were timed to coincide with holy days associated with St Mary, to whom the church was dedicated.


Its association with education was similarly important for Castletown, and as early as 1584 it was referred to as 'the Scholehouse'. In the late 17th century Bishop Isaac Barrow provided funds to establish a school, which his successor Bishop Thomas Wilson had moved into the building by 1708. Later it became known as the Grammar School to differentiate it from the nearby King William's College (founded in 1833 and similarly connected with Bishop Barrow) and continued in that role until 1930.


The school lies in the oldest part of Castletown and was threatened with demolition in the 1950s. The surrounding car park occupies the space created when all the other nearby structures were removed.


The building is protected both as an Ancient Monument and as a Registered Building (RB No. 073)