"The present church, though of early date, is believed to occupy the site of a still more ancient edifice, as we find it recorded by Simeon of Durham, that Edw or Edwine, a Northumbrian chief, who had exchanged his helmet for the cowl, died in 801, and was buried in the monastery of Gainford "in the church." Of this foundation there is no further mention made by any of our ancient historians, but it was doubtless a humble structure - perhaps made of wood - and, like many more monastic institutions formed previous to the Norman Conquest, of a temporary nature and with no settled or certain foundation. A more valuable and permanent establishment arose soon after this circumstance, for Egred, Bishop of Lindisfarne, 821-845, and owner of extensive possessions in this district, chose Gainford as the spot whereon to build a church and also a vill. Fragments of crosses, coeval with this date, are still to be seen within the church, and built into the walls.
"The church is dedicated to St. Mary, and its erection is ascribed to the community of St. Mary's Abbey, York, early in the thirteenth century. It is situated on the south side of the village green, and consists of nave, aisle, with north and south chancel, and a square western tower, containing six bells and a good clock. The tower is open to the nave, and is supported by pointed arches, and similar ones, of unequal span, resting on cylindrical pillars, separate the nave and aisles. The chancel opens from the nave, under a plain pointed arch, supported by corbels, beneath which are traces of the masonry on which the beam supporting the rood-loft formerly rested. In 1864, owing to the church having fallen into a bad state of repair, a thorough restoration was made, at a cost of over £3000. The chief alterations at this time were the erection of an organ chamber, with fine organ, and a north porch. During the repairs, a number of sculptured stones of pre-Conquest date were found, and are now placed under cover. There are several fragments of fine Saxon crosses also preserved, some of which are beautifully carved. Amongst the collection of ancient stones there is a Roman altar, dedicated to Jupiter Dolichenus, and a stone marked LEG VI. V. Various grave-covers, and other stones of later date are built into the walls of the north porch."
[From History, Topography and Directory of Durham, Whellan , London, 1894]