in the Civil Law, an estate left in trust with any person, for the use of another.

FIDENÆ (now CASTEL GIUBILEO), in Ancient Geography, an old and important Latin city, on the left bank of the Tiber, about five miles from Rome. It is said by Livy to have owed its origin to the Etruscans; but his testimony is not supported by that of any other historian. The idea of its Latin origin is that now generally received. The proximity of Fidenæ to Rome, and its jealousy of the rising power of that state, soon brought the two cities into collision; indeed there is no Latin city which plays so important a part in the annals of regal Rome as Fidenæ, which was not only powerful in its own resources, but by its connection and alliances with other Latin states. Hostilities first broke out between the two cities in the time of Romulus, and continued with little intermission and various success till 496 B.C., when, being abandoned by its allies, it was forced to yield to the Roman arms. In 438 B.C. the Fidenates revolted, slew the Roman ambassadors, and for twelve years maintained an unequal contest with their powerful neighbours. At the end of that time, however, their city was taken and plundered, and the inhabitants sold into slavery. From this time Fidenæ appears no more in history as an independent city. In the later times of the republic and under the empire, Fidenæ continued a small country village, and is mentioned by Horace as almost proverbially lonely and desolate. In the reign of Tiberius it acquired a dismal notoriety from a fearful accident which happened in its neighbourhood. An extraordinary gladiatorial show had attracted vast multitudes of spectators from Rome and the surrounding country, and the temporary wooden amphitheatre in which they were accommodated fell during the exhibition, and destroyed nearly 50,000 persons. No ruins of Fidenæ now exist; but the site of the city has been ascertained beyond a doubt at the modern Castel Giubileo.