Whatever the precise stimulus and the exact date of the migration of the village to its present site, it must have occurred in time to create the medieval field system. Butterworth argues that the most likely date would have been around 1340 to coincide with the construction of Howgill castle, although he accepts that an earlier date, prompted by raids into England by De Bruys in 1311 would also be possible. He points out that once the Lancasters became Lords of the Manor soon after 1335, they had a direct vested interest in protecting both their tenants and their tenants livestock, so that the laying out of a defensible village and the building of Howgill Castle might have gone hand in hand