Castor, a village and an ecclesiastical parish in Northamptonshire. The village stands on Ermine Street, adjacent to the river Nen, 5 miles W of Peterborough, and has a station on the L. & N.W.R., and a post and money order office under Peterborough; telegraph office, Peterborough. It occupies part of the site of the Roman station Durobrivse, and was known to the Saxons as Castra or Dormunde-Coestrc. A nunnery was founded at it in the 7th century by a daughter of King Penda, and destroyed in 1010 by the Danes. The parish contains also the hamlet of Ailesworth. Population, 920. The living is a rectory in the diocese of Peterborough ; net yearly value, s£366 with residence, in the gift of the Bishop of Peterborough. The church is Norman, with highly Decorated Norman tower, said to be the finest in England. The spire is unique and of 14th century work. It exhibits curiously the features and decorations of the Norman period. The vicarages of Sutton and Upton, formerly chapelries, are now separate charges. Bishop Madan was rector. There are Congregational and Free Methodist chapels. Milton House, about 1 ½ mile from the village, a fine country seat of the "Wentworth-Fitzwilliam family, stands in a park of 600 acres.