Vercellae (or Vercelum) was the capital of the Libici or Lebecili, a Ligurian tribe; it became an important municipium, near which Gaius Marius defeated the Cimbri and the Teutones in the Battle of Vercellae in 101 BC.
The imperial magister militum Flavius Stilicho annihilated the Goths there 500 years later. It was half ruined in St. Jerome's time (olim potens, nunc raro habitatore semiruta (1, 3.1)). After the Lombard invasion it belonged to the Duchy of Ivrea. From 885 it was under the jurisdiction of the prince-bishop, who was a Count of the Empire.
It became an independent commune in 1120, and joined the first and second Lombard leagues. Its statutes are among the most interesting of those of the medieval republics. In 1197 they abolished the servitude of the glebe. In 1228 the University of Pavia was transferred to Vercelli, where it remained till the fourteenth century, but without gaining much prominence; only a university school of law has been maintained.
In 1307, Fra Dolcino, the leader of the Dulcinian was tortured and burned at the stake.
During the troubles of the 13th century it fell into the power of the Della Torre of Milan (1263), of the Marquesses of Monferrato (1277), who appointed Matteo I Visconti captain (1290–1299). The Tizzoni (Ghibellines) and Avogadri (Guelphs) disputed the city from 1301 to 1334. The Guelphs were expelled several times, enabling the Marquess of Monferrato to take Vercelli (1328), which voluntarily placed itself under the Viscount of Milan in 1334. In 1373, Bishop Giovanni Fieschi expelled the Visconti, but Matteo reconquered the city. Facino Cane (1402), profiting by the strife between Giovanni Maria and Filippo Maria Visconti, took Vercelli, but was driven out by Theodore II of Montferrat (1404), from whom the city passed to the dukes of Savoy (1427).
In 1499 and 1553 Vercelli was captured by the French, and in 1616 and 1678 by the Spaniards. In 1704 it sustained an energetic siege by the French, who failed to destroy the fortress, after which it shared the fortunes of Savoy. In 1821 Vercelli rose in favour of the Constitution.