During the 14th century considerable rebuilding took place at the west end of the Abbey. A sketch of the great west window made in 1658 by Francis Sandford shows a selection of coats of arms that seem to suggest it was glazed around 1388, in the time of Stevens, who may also have been responsible for some of the other 14th century alterations. He was on good terms with the king, Richard II, who attributed his grant of a charter in 1389 not only to his own devotion to St Winifred, but also "the sincere affection we bear and have to Nicholas the abbot, and for his merits."