Procession to Commemorate the Dedication of a Church, in the 'Wormald Processional'
Medium: Ink and pigments on vellum
Processions often take place before masses on Sundays and important feasts. The procession, accompanied with chants, may be made to another church (a station), for readings and prayers. The processions' hymns are sometimes assembled in a book called a processional. Made for an urban church dedicated to St Mary and with dependent suburban churches, this one may have been for Salisbury Cathedral, but one of its processions is adapted for the tradition (use) of Norwich and a procession with the relics of St Swithin suggests Winchester, too.
The day of the dedication of a church was celebrated as a special feast. This page gives instructions, music and hymns for processions celebrating the church's dedication to St Mary. This indicates that the cathedral for which the processional was made was dedicated to St Mary, which unfortunately does not narrow the field of possibilities very much.