Cathedral Chapter House

The Cathedral Chapter House is part of the Cathedral Church of the Holy and Indivisible Trinity, and originates from the former Benedictine Priory of St Peter. Construction began around 1100, with a significant rebuilding in the late 12th century, and alterations in the 14th century. It is built of ashlar and has a stone slate roof with coped gables.

The building is a large chamber situated on the east side of the Cathedral Cloister, positioned between the Treasury and the Cathedral Library to the south, and the former abbey dormitory to the north. Originally comprising three 12th-century bays, it featured an apsidal east end. This apse was replaced in the 15th century by a fourth bay with canted sides. The entrance at the west end, from the east alley of the cloister, was also remodelled in the 15th century. A projecting stair to the library is incorporated into the north-west corner, with remains of a stair to the dorter on the north side.

The west gable-end wall features a 12th-century window with three large, stepped, semi-circular arched lights recessed below a segmental relieving arch. Nook shafts with cushion capitals support the mullions, and the central arch is decorated with chevron enrichment. The east gable-end wall contains a large nine-light window with Perpendicular tracery, a central transom, and foiled arched heads to the lights above and below the transom. At the north-east corner, a section of the former monastic dormitory's south wall remains, displaying the moulded jamb of a window decorated with ball flower.

Inside, above a continuous ashlar plinth, the three 12th-century bays are defined by wall shafts with scalloped capitals and transverse ribs supporting a pointed barrel vault. A pair of shafts and ribs are located at the east end of the east bay. A tall dado of three bays of blank arcading is situated between the wall shafts in each bay, capped by a string course. The two eastern arches of the arcading in the east bay on each side are decorated with chevron moulding. The 15th-century canted east bay is faced with Perpendicular arched panels, echoing the pattern of the east window. Wall shafts at the corners of the bay support an elaborate lierne vault with carved bosses. The canted east bay required outward projection to support the north-east and south-east corners of the east elevation on the Romanesque crypt walls below. The 14th-century east window replaced the earlier 12th-century apse. A section of early Romanesque pier is visible in the second pier from the north-east corner at Tribune level.