Ivrea (anc. Eporedia), a town and episcopal see of Piedmont, Italy, in the province of Turin, from which it is 38 m. N.N.E. by rail and 27 m. direct, situated 770 ft. above sea-level, on the Dora Baltea at the point where it leaves the mountains. Pop. (1901) 6047 (town), 11,696 (commune). The cathedral was built between 973 and 1005; the gallery round the back of the apse and the crypt have plain cubical capitals of this period. The two campanili flanking the apse at each end of the side aisle are the oldest example of this architectural arrangement. The isolated tower, which is all that remains of the ancient abbey of S. Stefano, is slightly later. The hill above the town is crowned by the imposing Castello delle Quattro Torri, built in 1358, and now a prison. One of the four towers was destroyed by lightning in 1676. A tramway runs to Santhià.
The ancient Eporedia, standing at the junction of the roads from Augusta Taurinorum and Vercellae, at the point where the road to Augusta Praetoria enters the narrow valley of the Duria (Dora Baltea), was a military position of considerable importance belonging to the Salassi who inhabited the whole upper valley of the Duria. The importance of the gold-mines of the district led to its seizure by the Romans in 143 B.C. The centre of the mining industry seems to have been Victumulae (see Ticinum), until in 100 B.C. a colony of Roman citizens was founded at Eporedia itself; but the prosperity of this was only assured when the Salassi were finally defeated in 25 B.C. and Augusta Praetoria founded. There are remains of a theatre of the time of the Antonines and the Ponte Vecchio rests on Roman foundations.
In the middle ages Ivrea was the capital of a Lombard duchy, and later of a marquisate; both Berengar II. (950) and Arduin (1002) became kings of Italy for a short period. Later it submitted to the marquises of Monferrato, and in the middle of the 14th century passed to the house of Savoy.
