The city's name appears for the first time as Bugella in a document of 826 recording to the donation of Bugella to Count Busone by Louis the Pious, son of Charlemagne, Holy Roman Emperor. In the 10th century the town was inhabited by Alemanni, Lombards and Franks, who built the first walls as a defense against barbarian invasions. On April 12, 1160, Uguccione, bishop of Vercelli, granted important trade privileges to anyone residing on Piazzo hill: this was the birth of the Borgo del Piazzo. Bishop Uguccione's castle was destroyed in a revolt in 1377 that led to the subjection of Biella, along with its dependent comuni, to the house of Savoy.
In the 14th and 15th centuries the Visconti family competed with Savoy for the possession of the Biella area. The 17th century saw a similar competition between French and Spanish forces; in 1706 Pietro Micca, a Biellese soldier, saved nearby Turin from a siege that would have meant the invasion of Biella by the French as well — but paid for it with his own life.
In 1798 Biella was once again occupied by the French, and after the battle of Marengo, Biella was formally annexed by France. The Congress of Vienna returned it to Savoy. In 1859 Biella was besieged by the Austrians but Garibaldi forced an end to the siege, and the town became part of the province of Novara, and was transferred to the province of Vercelli in 1927.
