Misericords and their Purpose
The priests at Holy Trinity were Augustinian canons, who were governed by the rules (or canons) of the church and answered to the Bishop of Worcester. Their commitment was to sing the eight daily offices in the chancel of the church: Matins, Lauds, Prime, Terce, Sext, Nones, Vespers and Compline, as well as celebrating one or two high masses.
It was Dean Thomas Balsall who completely rebuilt the chancel between 1466 and 1491, and installed the misericords.
The priests had to stand for all services, except for the Epistle and Gradual at Mass and the Response at Vespers. This was particularly hard on older or weaker priests and so misericords evolved to help those who were not able to stand for long periods. Effectively, they were an early form of tip-up seat comprising a normal wooden hinged seat with a small ledge on its underside, big enough to support a person's weight.
An infirm or elderly priest could therefore rest on the small seat during services and yet appear to be standing. The extraordinary carvings are only visible when the seat is folded up. The name "misericord" is derived from the Latin word miserere meaning "mercy".