23 Here it might be helpful to allude to the earliest legal structures associated with the service of charity in the Church. Towards the middle of the fourth century we see the development in Egypt of the “ diaconia ”: the institution within each monastery responsible for all works of relief, that is to say, for the service of charity. By the sixth century this institution had evolved into a corporation with full juridical standing, which the civil authorities themselves entrusted with part of the grain for public distribution. In Egypt not only each monastery, but each individual Diocese eventually had its own diaconia ; this institution then developed in both East and West. Pope Gregory the Great († 604) mentions the diaconia of Naples, while in Rome the diaconiae are documented from the seventh and eighth centuries. But charitable activity on behalf of the poor and suffering was naturally an essential part of the Church of Rome from the very beginning, based on the principles of Christian life given in the Acts of the Apostles . It found a vivid expression in the case of the deacon Lawrence († 258). The dramatic description of Lawrence's martyrdom was known to Saint Ambrose († 397) and it provides a fundamentally authentic picture of the saint. As the one responsible for the care of the poor in Rome, Lawrence had been given a period of time, after the capture of the Pope and of Lawrence's fellow deacons, to collect the treasures of the Church and hand them over to the civil authorities. He distributed to the poor whatever funds were available and then presented to the authorities the poor themselves as the real treasure of the Church. Whatever historical reliability one attributes to these details, Lawrence has always remained present in the Church's memory as a great exponent of ecclesial charity.
Source: Deus Caritas Est (Vatican.va)