In considerations of the way in which commercial transactions during the Middle Ages accorded with moral laws, the significance of the direct economic power wielded by the Church on account of her great material possessions is often disregarded. The early Church accumulated little property; this was to ai certain extent connected with the marked chiliastic attitude adopted during the first few centuries, and the Church was fully occupied in spreading her doctrine as widely as possible. In the late second century Clement of Alexandria not only upheld the institution of private property but declared that it was justifiable for Christians to amass large fortunes. There was a law dating from A.D. 321 allowing anyone at death to leave what property he wished to the Church. Statutes such as this favouring the incipient Church in Constantinople marked the beginning of an acquisition of wealth that in the Middle Ages was unrivalled by any other corporation or individual, and this accumulation of riches by the Church was even more marked in England than elsewhere.

The period of the Crusades brought a great increase in ecclesiastical property, for many raised money from the Church on the security of their lands and as a fair proportion never returned their lands reverted to the Church. This process went on for two centuries. In England for centuries before the Reformation the pious rich had been heaping up treasures for the clergy by gifts and endowments, and this tendency towards accumulating worldly wealth coupled with the policy of never alienating it made the Church a great business as well as religious corporation with interests touching the whole economic life of the people.