Ancaster was a small town in the Roman province of Britannia. It is sited on the Roman road known as the Ermine Street and is situated in the county of Lincolnshire. Its name in Latin is unknown, although it has traditionally been identified with Causennis or Causennæ, a name which occurs as a town on the route of Iter V recorded in the Antonine Itinerary. Rivet and Smith questioned this identification in 1979, and suggested that a more likely identification would be either the Roman settlement at Salters ford, near Grantham in Lincolnshire, or at Sapperton in Lincolnshire.