The upheavals of the Reformation and the Civil War of the mid-17th century see huge changes in the shape and life of the church
1539 At the Dissolution of the Monasteries patronage [responsibility] for the church passes from St Mary’s Abbey, York, to Trinity College, Cambridge
1547 The Chantries Act dissolves chantry chapels: St Mary’s loses chantries for St Mary, St Katherine and the Guild of the Holy Trinity, along with its priest who ran a grammar and song-school.
c.1559-61 Elizabeth I’s ‘Royal injunction’ orders the removal of pre-Reformation rood-lofts which held a large crucifix with the figure of Christ, and statues of Mary and the disciple John. St Mary’s doorway to the loft can still be seen.
1580 – The burial in the South Transept of Sir George Bowes who held Barnard Castle for Elizabeth I during the Rising of the North by Catholic nobility and commoners supporting Mary Queen of Scots.
1609 St Mary’s church registers of baptisms, weddings and funerals begin.
1603-1625 A new oak altar for communion is installed, standing on the original medieval altar slab with its five consecration crosses.
1670 A silver chalice and paten for communion is donated to St Mary’s by Maxtona Dawson, daughter of Thomas Bowes of Streatlam, after the safe delivery of her first son, George. The chalice is still used weekly in celebration of the Eucharist (Holy Communion).
1680 A porch with a pitched roof is added to the South Door.