Upton is a suburb of Slough, now in the Slough district of Berkshire but before the reforms of 1974 it was part of Buckinghamshire. The parish was formerly known as Upton cum Chalvey, and included both Chalvey and Slough, both small settlements. When the new civil parish of Slough was formed in 1894, Upton was a part of it. It forms the southern part of central Slough, between the centre and the M4.The church consists of a 12thc nave and chancel with a central tower. A separately roofed S aisle was added by Ferrey in 1850-51, with a vestry at its E end. Ferrrey also replaced the nave windows on the N side in a Romanesque style, replacing the 15thc windows that were there. The Romanesque church shows evidence of two phases. The first includes the tower and a shorter nave and chancel, all constructed using a large proportion of puddingstone. The nave had a N doorway and a window above it, both now blocked. When the church was extended E and W the doorway was moved a bay to the W. The chancel has a 2-bay rib vault belonging to the second phase. In addition to the N doorway the arcaded 12thc font, a pillar piscina in the chancel and the chancel vault remain to be recorded when access to the interior has been gained.

The manor was held by Earl Harold before the Conquest and by the king in 1086. It was assessed at 18 hides. It later passed to the Beauchamp family, a member of which, Payn de Beauchamp, gave it to Merton Priory, perhaps as a foundation gift soon after 1125. It remained with that house until the Dissolution.

The extent to which the N doorway has been restored is a matter of conjecture. For both the author of the List Description and the RCHME, only the inner, limestone order and the angle shafts are original, while the outer order of clunch is modern. It is clear too that the label is more recent than the rest of the limestone work. If this is the case, the only reliable diagnostic feature, the flat leaf capitals (stylistically after c.1170), would be useless for dating purposes. Much depends on whether any of the early 12thc doorway was re-used when its position was changed. if this were so, the clunch angle roll in the 2nd order arch would be the only candidate. Pevsner (1994) was content simply to describe it as 'restored' and he was a wise man.