The name comes from the Cornish 'hen lis' or 'old court' and 'ton' added later to denote a Saxon manor; the Domesday Book refers to Henliston (which survives as the name of a road in the town). Only one edition refers to 'Henlistona'. It was granted its charter by King John on 15 April 1201, for the price of forty marks of silver. It was here that tin ingots were weighed to determine the tin coinage duty due to the Duke of Cornwall when a number of stannary towns were authorised by royal decree. A document of 1396 examined by Charles Henderson shows that the old form "Hellys" was still in use The manor of Helston in Kerrier was one of the seventeen Antiqua maneria of the Duchy of Cornwall. The seal of the borough of Helston was St Michael his wings expanded and standing on a gateway. The two towers domed upon the up-turned dragon, impaling it with his spear and bearing upon his left arm an escutcheon of the arms of England, viz Gu three lions passant guardant in pale Or, with the legend ""Sigillum comunitatis helleston burg"".