From The Warminster Official Guide And Souvenir 1928 (penned by Victor Strode Manley):
Under the Normans, Warminster continued a royal manor free from taxes on condition of lodging the King and his retinue when required. The town grew up around the Parish Church, the market being at Emwell Cross (Obelisk). The Saxon name of the town was WORGEMYNSTER, changed in Domesday to GUERMINSTRE.