BOLSENA (anc. Volsinii),  a town of the province of Rome, Italy, 12 m. W.S.W. of Orvieto by road, situated on the north-east bank of the lake of Bolsena. Pop. (1901) 3286. The town is dominated by a picturesque medieval castle, and contains the church of S. Christina (martyred by drowning in the lake, according to the legend, in 278) which dates from the 11th century and contains some frescoes, perhaps of the school of Giotto. It has a fine Renaissance façade, constructed about 1500 by Cardinal Giovanni de' Medici (afterwards Pope Leo X.), and some good terra cottas by the Della Robbia. Beneath the church are catacombs, with the tomb of the saint, discovered in 1880 (E. Stevenson in Notizie degli Scavi, 1880, 262; G.B. de Rossi in Bullettino d'Archeologia Cristiana, 1880, 109). At one of the altars in this crypt occurred the miracle of Bolsena in 1263. A Bohemian priest, sceptical of the doctrine of transubstantiation, was convinced of its truth by the appearance of drops of blood on the host he was consecrating. In commemoration of this Pope Urban IV. instituted the festival of Corpus Christi, and ordered the erection of the cathedral of Orvieto. The miracle forms the subject of a celebrated fresco by Raphael in the Vatican.
The Lake of Bolsena (anc. Lacus Volsiniensis), 1000 ft. above sea-level, 71 sq. m. in area, and 480 ft. deep, is almost circular, and was the central point of a large volcanic district, though it is probably not itself an extinct crater. Its sides show fine basaltic formation in places. It abounds in fish, but its banks are somewhat deserted and not free from malaria. It contains two islands, Bisentina and Martana, the former containing a church constructed by Vignola, the latter remains of the castle where Amalasuntha, the daughter of Theodoric, was imprisoned and strangled.
 According to the theory now generally adopted, the Etruscan Volsinii occupied the site of Orvieto, which was hence called Urbs vetus in late classical and medieval times, while the Roman Volsinii was transferred to Bolaena (see Volsinii).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)