In the fifteenth century definite pronouncements on rent charges were made by the Popes. A large part of the revenue of ecclesiastical bodies consisted of rent charges, and in 1425 several persons in the diocese of Breslau refused to pay the rents they owed to their clergy on the ground that they were usurious. The question was referred to Pope Martin V., whose bull deciding the matter was generally followed by all subsequent authorities. The bull decides in favour of the lawfulness of rent charges, provided certain conditions were observed. They must be charged on fixed property ('super bonis suis, dominiis, oppidis, terris, agris, praediis, domibus et hereditatibus') and determined beforehand; they must be moderate, not exceeding seven or ten per cent.; and they must be capable of being repurchased at any moment in whole or in part, by the repayment of the same sum for which they were originally created. On the other hand, the payer of the rent must never be forced to repay the purchase money, even if the goods on which the rent was charged had perished--in other words, the contract creating the rent charge was one of sale, and not of loan. The bull recites that such conditions had been observed in contracts of this nature from time immemorial.[1] A precisely similar decree was issued by Calixtus III. in 1455.[2] [Footnote 1: _Extrav. Commun._, iii. 5, i.] [Footnote 2: _Ibid._, c. 2.] These decisions were universally followed in the fifteenth century.[1] It was always insisted that a rent could only be charged upon something of which the use could be separated from the ownership, as otherwise it would savour of usury.[2] In the sixteenth century interesting discussions arose about the possibility of creating a personal rent charge, not secured on any specific property, but such discussions did not trouble the writers of the period which we are treating. The only instance of such a contract being considered is found in a bull of Nicholas V. in 1452, permitting such personal rent charges in the kingdoms of Aragon and Sicily, but this permission was purely local, and, as the bull itself shows, was designed to meet the exigencies of a special situation.[3] [Footnote 1: Ashley, _op. cit._, vol. i. pt. ii. p. 410.] [Footnote 2: Biel, _op. cit._, Sent. IV. xv. 12.] [Footnote 3: Cleary, _op. cit._, p. 124.] § 9. _Partnership_.