Although not well documented until the 13th century, it has always been assumed that there had been a castle at Bolingbroke since the 12th century. Excavations on the castle site (see PRN 43574) therefore prompted the thought that the site of the castle had been moved from an earlier location. There is an earthwork on Dewy Hill, 500 yards to the north of the present castle, that has been claimed as the site of the earlier castle. This earthwork is roughly rectangular and measures 120 yards long by 80 yards broad. In October 1965, five days were spent on this site trial trenching. Traces of 11th to 12th century occupation were found within the earthwork, (bones, sherds, a buckle and hone), although the earthworks themselves might be of earlier origin. The occupation is of the right date, but the evidence is still a little slender to speak of a castle. The site has been ploughed. {1}{2}{3}