Beauvais was known to the Romans by the Gallo-Roman name of Caesaromagus (magos is Common Celtic for "field".) . The post-Renaissance Latin rendering is Bellovacum from the Belgic tribe the Bellovaci, whose capital it was. In the ninth century it became a countship, which about 1013 passed to the bishops of Beauvais, who became peers of France from the twelfth century. At the coronations of kings the Bishop of Beauvais wore the royal mantle and went, with the Bishop of Langres, to raise the king from his throne to present him to the people.
In 1346 the town had to defend itself against the English, who again besieged it in 1433. The siege which it endured in 1472 at the hands of the Duke of Burgundy, was rendered famous by the heroism of the town's women, under the leadership of Jeanne Hachette, whose memory is still celebrated by a procession on 14 October (the feast of Sainte Angadrême), during which women take precedence over men.
An interesting hoard of coins from the High Middle Ages became known as the Beauvais Hoard, because some of the British and European coins found with the lot were from the French abbey located in Beauvais. The hoard, which contained a variety of rare and extremely rare Anglo-Norman pennies, English and foreign coins, was reputed to have been found in or near Paris.
De Bello Gallico II 13 reports that as Julius Caesar was approaching a fortified town called Bratuspantium in the land of the Bellovaci, its inhabitants surrendered to him when he was about 5 Roman miles away. Its name is Gaulish for "place where judgements are made", from *bratu-spantion. Some say that Braduspantium is Beauvais. Others theorize that it is Vendeuil-Caply or Bailleul sur Thérain