The article deals with the notarial act of 1295 that confirms the grant of a relic by the chapter of St Just of Lyons to the Florentine monastery San Giusto alle Mura. The primary attention is paid to the reasons that prompted the canons to give a part of the relics to a little known monastery. It is an attempt to ascertain the circumstances of the deal that were not reflected in the document. The substituted data allows us to conclude that at the end of the 13th century the chapter of St Just was in a difficult financial situation. The grant of the relic was accompanied by large expenses on the part of its initiator, Florentine of Lyons Bernarduccio Aldobrandeschi. It is possible to assume that the chapter actually sold the relic, having probably paid thus their unsettled debts. Taking in account the value of the object of the transaction and its questionable character, the canons got advantageous terms. The sale was presented as a conditional gift, the notarial act underlined unselfish motives of the canons, and the recipients of the gift guaranteed a proper respect of the relic. Formally the aim of the grant was to disseminate the cult of the saint, although the canons could count on this in addition to other benefits of the transaction. Despite the efforts of the Florentines, the possession of the relic did not help the nuns to improve the status of their monastery and get the preference in their dispute with a local parish patron.