St Peter's has a nave with N and S aisles of three bays. In each arcade the arches of the two W bays, and the westernmost pier and respond are 12thc. (the N stylistically earlier than the S); the eastern arch, pier 1 and the east respond belong to the later 13thc. The remodelling is visible on the outside too, with big ashlar blocks at clerestorey level at the west end and smaller, roughly-shaped blocks to the east. The clerestorey itself is 14thc. The chancel also belongs to the 13thc., and the nave aisles have been extended eastwards alongside it forming chapels; the S screened off as a vestry and the N walled off from the nave aisle. The N and S doorways are both protected by porches. The west tower has one 13thc. lancet, but is otherwise apparently of the early 14thc., with a Perpendicular parapet. 12thc. sculpture is found in the west bays of the arcades.

In 1086 Eustace held 1 hide and 2½ virgates by force, to the detriment of the Church of Ramsey, a similar sized holding was in the hands of Ralph, who held it from Guy de Raimbeaucourt, and Walkelin held 3 virgates from the Bishop of Coutances. No church was noted.

Benefice of Isham with Pytchley.

The 12thc. parts of the S arcade are stylistically later than the N. Not so much in the capital forms, which could easily be contemporary, as in the change from one-order to two-order arches and from chamfered to hollow-chamfered imposts.