St Andrew's has a four-bay aisled and clerestoreyed nave with arcades ofc.1300, the N stylistically later than the S. At the W end the tower is entered by a small 13thc. doorway rather than an arch. The chancel and its arch are 14thc. Construction is of irregular grey stone blocks. The W tower is of three storeys, containing features of the 12thc. but rebuilt. Signs of the rebuilding are most obvious on the W face, which has a central flat buttress extending halfway up the first storey. The wall to the S of this is built in three steps divided by string courses above a plinth course; to the N the wall is not articulated. The tower has 12thc. windows and bell-openings, described below, a string course, and a row of corbels well below the present upper parapet.

The manor was held by Countess Judith in 1086. No church was recorded.

Benefice of Yardley Hastings, Denton and Grendon with Castle Ashby and Whiston.

The W tower must have been remodelledc.1200, and at that date the present lower lancet and bell-openings were added. At a later date the top was rebuilt and the embattled parapet added. When this was done, the upper courses of the tower were dismantled, and the existing corbels built in. They belong to various periods, and it is not certain that they all came from the tower originally. The demon's head (N6), 'werewolf' (NW angle) and green man (W1), for example, are late-medieval, whereas the roll corbels (S1, N2, N4) and most of the heads are Romanesque. The bell-openings and the use of nailhead relate this church to nearby Bozeat.