The later years of the 14th and the earlier years of the 15th centuries were characterised by particular prosperity. It is in this period that the York Mystery Plays, a regular cycle of religious pageants (or plays) associated with the Corpus Christi cycle and performed by the various craft guilds grew up. Among the more important personages associated with this period was Nicholas Blackburn senior, Lord Mayor in 1412 and a leading merchant. He is depicted with his wife Margaret Blackburn in glass in the (now) east window of All Saints' Church in North Street. There seems to have been economic contraction and a dwindling in York's regional importance in the period from the later 15th century. The construction of the city's new Guildhall around the middle of the century can be seen as an attempt to project civic confidence in the face of growing uncertainty. Brandsby-type ware and Humber ware ceramics were popular in the city at this time.