FIEF, ECCLESIASTICAL: A term used sometimes as equivalent to Benefice (q.v.), but more properly designating an estate belonging to the Church and conferred by feudal tenure. Military service was included in the obligations of a true fief, even when held by a cleric--but in this case, as the canons forbade him to bear arms, he was allowed to provide a substitute. The practise of granting church lands attained such proportions during the Middle Ages that Pius V., in 1567, prohibited any further grants, providing for the immediate incorporation with the papal camera of any fiefs that fell in. On this principle Clement VIII. incorporated the duchy of Ferrara with the States of the Church in 1598, and Urban VIII. did the same with Urbino, Castro, and Ronciglione. Famous instances of countries held by their rulers as vassals of the pope were Aragon (1208), England (1213), the island of Sardinia (1295), Naples and Sicily down to the second half of the eighteenth century.