St Michael'S Mount

St Michael's Mount is a priory castle, lady chapel and private house of exceptional architectural and historical importance. Built around 1135 for Bernard of Le Bec, it was substantially remodelled in the 14th and 15th centuries, then comprehensively remodelled and extended around 1870 by Piers St Aubyn. The building is constructed of granite rubble with granite dressings, roofed with scantle slate and dry Delabole slate with gable ends and embattled parapets to most roofs. Dressed granite chimneys, mostly of the 19th century and irregularly disposed, project above the roofline. The 19th century extensions are carried on brick vaults supporting flat roof terraces.

The plan is irregular, largely determined by the rocky outcrop on which the building stands. The earlier domestic parts occupy an L-shaped block comprising a south range perched over a precipitous slope and a west entrance range. The west range has projecting towers at either end with the main entrance positioned between them on the left hand side. The entrance occupies the thickest walling and is defended by a portcullis. To the right of the entrance lies the Armoury, formerly a hall, behind which stands the Church of Saint Michael at right angles. A thick buttress projects from the left hand tower, possibly the truncated remains of an outer entrance or gatehouse. In the outer angle between the west and south ranges sits a square block, probably formerly a tower, featuring a garderobe on corbels or machicolations. Behind this block, now known as Sir John's Room, a lobby leads to the Library, which is a 18th century remodelling of probably a former tower with access to the church. Adjoining the rear right hand corner of the Breakfast Room is the former monks' refectory, reroofed in the 15th century, embellished in the 17th and 18th centuries, and known since the 17th century as the Chevy Chase Room. Beneath this room lies the Garrison Room. The building features varied floor levels throughout, linked by several straight flights of stairs and granite newel stairs.

Around the late 15th century, a Lady Chapel was built adjoining the north-east corner of the church. This was remodelled around 1760 and now contains the Blue Drawing Rooms. Around 1826, the outer defences on the east and north sides were remodelled to provide walks with granite balustrades around the lady chapel and in front of the north doorway of the church.

This process of extending the outer walls continued in the 1870s with the addition of terraces filling the south-east angles and areas north and north-west of the church. By exploiting the steep slopes of the mount, these extensions provided greatly increased accommodation, rising five floors high at the south-east corner, all below the floor level of the Chevy Chase Room. The south-east block comprises reception rooms and chambers over a basement entrance floor, with levels linked by a round newel stair turret. The area north of the church forms a service wing, including the kitchen, now the Museum. Contemporary with these extensions, much of the old fabric was refloored and reroofed, with new Gothic style windows added to existing openings or newly cut or enlarged ones. A link building connects the Blue Rooms to the Long Passage south of the church, leading to a large stair turret in the angle between the church, the Breakfast Room and the Chevy Chase Room. At the east end of the Chevy Chase Room (the Smoking Room), 19th century rebuilding includes the addition of an oriel window in the south wall.

The west wall contains much early masonry, with the central wall battered halfway up and displaying granite weathering. Above the wall stands the remains of a corbelled parapet above the 19th century windows. A 4-centred arched doorway, probably of the 16th century, features a pistol loop in the left tower. Above the doorway are the St Aubyn Arms (St Aubyn impaling Godolphin) dated 1660. An impressive flight of granite steps leads to the entrance.

The south wall is the least altered elevation, rising sheer from the steep side slope of the mount. Window openings are mostly small, with 15th or 19th century windows replacing earlier lancets. To the right of the Garrison Room is an arched opening, possibly a former garderobe outlet. The rear (east) wall of the west range retains some earlier mullioned windows. The north wall of the Chevy Chase Room has one 15th century window to the main wall on the right and 15th century windows to either side of a small north transept, with other later windows. The middle window contains fine glass of 15th century and later date, brought to the mount in the 18th century.

The former Lady Chapel features Y-traceried windows fitted with 18th century sashes with wide geometric glazing bars. Other 18th century sashes are found elsewhere on the mount, though similar examples in the library are 19th century copies. Some late 19th century plaster embellishments appear above the windows and to the parapet.

The interior contains several features of architectural note. The Chevy Chase Room displays a fine 15th century arch-braced roof structure, a 17th century plaster frieze depicting the Chevy Chase, a 17th century coat of arms and fine 18th century Gothic style plasterwork. A 16th century doorway connects this room to the Breakfast Room, and a doorway to a probably 15th century newel stair descends to the garrison room below.

The Blue Drawing Rooms feature fine 18th century Gothic style plasterwork and details. The entrance hall has a quatrefoil-on-square plan with vaulted plasterwork. The large drawing room displays a barrel-vaulted ceiling with a trefoiled arcade to the cornice, and a chimneypiece with ramped pediment to the overmantle and ogee-headed architraves. The small drawing room has a panelled plaster ceiling with modillioned cornice, vaulted plasterwork to the bay window at the east gable end, and an unusual chimneypiece with latticed detail and breaks in the entablature.

St Michael's Mount occupies a unique situation with no other comparable building in England. Despite 19th century accretions, the medieval core remains very prominent and largely intact, making this an exceptional survival of ecclesiastical and domestic architecture spanning nearly nine centuries.