The Chapter-House, which lies to the north of the choir, is approached by a vestibule which has a doorway, already described, into the third bay of the north choir aisle. Both the chapter-house and the vestibule were built at the same time as the north transept—that is, somewhere near the middle of the thirteenth century—and the style is therefore that known as the Early English, but it is a later instance than that part of the choir into which the doorway leads. That the vestibule was not built when the early part of the choir was finished is evident, as "its walls abut against those of the choir with a straight joint, and the arch of entrance in the side aisle is a manifest intrusion into the space once occupied by a window." The north end of the vestibule has also been altered, there having been a doorway where now there is a window; the former existed until nearly the end of the last century, but it had been altered before the plate in Britton's "Cathedrals" was engraved. It can easily be seen from the outside that such a door must have existed, from the different colouring of the stone-work. The window has recently been filled with stained glass by Messrs Burlison & Grylls, representing Nehemiah and Simeon, in memory of the late verger, William Yeend. Down each side of the vestibule there is a very fine arcading, that on the west side being double and much deeper than that on the east, which is single; the niches are large enough to be used as seats, and it has been suggested that here the ceremony of washing the feet of the poor took place on Maundy Thursday; as there were thirteen niches, this is highly probable. Some of the capitals of the pillars of the arcade are very finely carved, and, as was usual at the time, are very deeply under-cut; and the dripstones terminate in very interesting corbels in the form of heads and bunches of foliage. Recently, on the west side, some of the arcading has been opened out to afford access to the new vestry, which has been constructed by roofing in the space between the vestibule and the north transept. On the east side near the cathedral is the entrance to the library, which is the upper storey of the chapter-house building, and is approached by a spiral staircase. At the farther end, on the same side, is the very fine entrance to the chapter-house. This, like the central west doorway and that in the north transept, is double and recessed. The mouldings in the arch are deeply and finely cut, and the capitals of the grouped shafts are very richly carved with delicate leaves. The jambs have an enrichment of dog-toothing behind the slender detached shafts, and the two small arches have trefoil archivolts, so that the whole has a very rich effect. In the tympanum of the arch there is a bas-relief figure of Our Lord in a quatrefoil recess.
The chapter-house is a very fine room; it is octagonal in shape, but the north and south sides of it are double the length of each of the other six sides, which are equal. There is a central pillar, the clustered shafts of which are banded in the centre; the capitals of these shafts have a particularly rich and elaborate carving of foliage; and above, the vaulting ribs spread to the roof like the branches of a tree, producing a very fine effect. The bosses where the ribs intersect are also worthy of attention, and the ribs rise from very richly-carved and deeply-moulded corbels. The windows are Early English, and of two lights each. Below is a very beautiful arcading, similar, indeed, to that in the vestibule, which entirely surrounds the building. The arcade is composed of deep, moulded, trefoil arches, resting on single columns, with beautifully-carved capitals, in some of which will be found figures of birds and animals. The canopies of the arches are dog-toothed, and end in curiously-carved heads, which afford interesting illustrations of the head-dresses of the time.
The chapter-house was decorated with frescoes and stained glass by Dean Heywood in the fifteenth century, as we know from the MSS. entitled Cantaria Sancti Blasii in the library. The frescoes have disappeared except over the doorway, where still remain faint signs of the representation of the Assumption, which may have formed part of Dean Heywood's decoration, but more likely is earlier: it has been suggested that it was placed there by Bishop Burghill from the fact that a Dominican Friar, to which order he belonged, is represented in the group in adoration. The glass contained figures of the apostles, with other pictures above; these being all pre-Cromwellian, have, of course, disappeared. More recently the glazing of the chapter-house displayed armorial bearings, more or less correct, in imitation of glass known to have ornamented the cathedral in the past. This armorial glass is gradually giving way to glass representing scenes in the history of the cathedral. At present, five of the windows have been so glazed, and the rest will be changed gradually, as opportunity offers.
The first window on the left-hand side on entering is in memory of Prebendary Edwards. There are figures of St. Chad and King Wulphere, with scenes showing the Consecration of St. Chad, and the Baptism by St. Chad of the two sons of King Wulphere.
The second window is in memory of Archdeacon Allen and Prebendary de Bunsen. The figures are St. Oswald and St. Aidan. The scenes represent St. Aidan preaching to the Northumbrians, with King Oswald interpreting; and St. Aidan at Lindisfarne, teaching in his school, where St. Chad is one of the scholars.
The third window is in memory of Dean Bickersteth. The figures are Archbishop Theodore and St. Ovin, and the scenes St. Chad teaching his clergy, and St. Ovin listening to the angels who were calling St. Chad at his death.
The fourth window is in memory of Prebendary Gresley. The figures are Oswy, King of Northumbria, and Diuma, the first bishop of Mercia. The scenes are Bishop Jaruman promising to build a church at Lichfield, and the institution by King Æthelwald of prebendaries.
The fifth window is in memory of Prebendary Finch Smith. The figures represent Archbishop Higbert of Lichfield, and Thomas Cantelupe, Bishop of Hereford, formerly prebendary of this cathedral. The scenes are Bishop Aldulf at the Council of Cloveshoo, renouncing the metropolitan powers in favour of Canterbury, and Bishop Roger de Clinton building a new cathedral in honour of St. Mary and St. Chad.