BIEDA. – An ancient episcopal city of Latium, in the province of Viterbo, situated on a tuffaceous plateau at the confluence of the Biedano stream and the Rio Canale; it is crossed by the Via Clodia and lies not far from the Cassia. The Romans called it Blera or Bleva, and under them it retained the prosperity acquired during the period of its Etruscan civilization, as the discovery of the necropolis, inscriptions, and other monumental remains has testified. Its decline must have occurred in the early Middle Ages, caused, without doubt, by the neighboring cities, which were more accessible because of their topographical position. In the first half of the 8th century B. was the property of the Holy See; it was occupied in 739 by the Lombards, but soon restored by King Liutprand to Pope Zacharias; in 772 Desiderius conquered it again, until, two years later, with the destruction of the Lombard kingdom in Italy, it definitively became part of the Patrimony of St. Peter.
The origin of Christianity in B. is linked to the name of St. Senzio, whose Vita (BHL 7581-82b), written between the 7th and 8th centuries by monks, probably from the Tuscan archipelago, presents him as a monk who evangelized B. and died toward the end of the 5th century, after overcoming the pagan resistance of its citizens. His name is found in the Martyrologium Hieronymianum on 25 May, and De Rossi suspects that St. Senzio predates the middle of the 5th century. Lanzoni, for his part, regards him as a martyr of the persecutions, who only during the golden age of monasticism in Tuscany was celebrated by the anonymous author of the Vita as a monk of the 5th century.
The origin of Christianity in B. thus depends chronologically on the time in which St. Senzio is supposed to have lived, and he may be regarded as the evangelizer of the Biedan territory. The first bishop of B. known to us is Massimino, who appears among the signatories of the Roman synods from 487 to 502. B. was the birthplace of Pope Sabiniano (Lib. Pontif., ed. L. Duchesne, I, p. 315); St. Gregory the Great recalls (Reg., IX; Ep. 96 in MGH, Epist., II, p. 106) an abbey in its territory, of which, however, no trace remains; while a church in honor of St. Senzio must have arisen in B. at an early date, which Leo IV had decorated in the 9th century (Lib. Pontif., ed. cit. II, p. 125). In 1093 Bishop Riccardo still bore the title of B., but had already TOSCANA (v.). In 1192 Celestine III, establishing the bishopric of Viterbo, also annexed to it the ancient dioceses of Tuscania, Civitavecchia, and B., ordering that the holder of the new diocese bear the title of Bishop of Viterbo and Tuscania.