4. Right from the most ancient times, as a matter of fact, if we may sketch out a few lines of history, the Roman Pontiffs, in the course of their service directed to the welfare of the whole Church, have engaged the help of institutions or individual men selected from that Church of Rome which our predecessor Gregory the Great has called the Church of the Blessed Apostle Peter.

At first they used the services of priests or deacons belonging to the Church of Rome to function as legates, to be sent on various missions, or to represent the bishops of Rome at ecumenical councils.

When matters of particular importance were to be dealt with, the bishops of Rome called on the help of Roman synods or councils to which they summoned bishops working in the ecclesiastical province of Rome. These councils not only dealt with questions pertaining to doctrine and the magisterium, but also functioned like tribunals, judging cases of bishops referred to the Roman Pontiff.

From the time when the cardinals began to take on a special importance in the Roman Church, especially in the election of the Pope — a function reserved to them from 1059 —, the Roman Pontiffs made more and more use of their services, with the result that the Roman synods and councils gradually lost their importance until they ceased entirely.

So it came about that, especially after the thirteenth century, the Supreme Pontiff carried out all the business of the Church together with the cardinals gathered in consistory. Thus temporary instruments, the councils or synods of Rome, were replaced by another instrument, a permanent one, always available to the Pope.

It was our predecessor Sixtus V who gave the Roman Curia its formal organization through the above-quoted Apostolic Constitution Immensa æterni Dei, on 22 January 1588, the 1587^th year from the Incarnation of Our Lord Jesus Christ. He set up fifteen dicasteries, so that the single College of Cardinals would be replaced by several colleges consisting of certain cardinals whose authority would be confined to a clearly defined field and to a definite subject matter. In this way, the Supreme Pontiffs could enjoy maximum benefit from these collegial counsels. Consequently, the consistory’s own original role and importance were greatly diminished.

As the centuries passed and historical outlooks and world conditions were transformed, certain changes and refinements were brought in, especially when the commissions of cardinals were set up in the nineteenth century to give the Pope assistance beyond that of the other dicasteries of the Roman Curia. Then on 29 June 1908, our predecessor Saint Pius X promulgated the Apostolic Constitution Sapienti consilio, in which, referring to the plan of collecting the laws of the Church into a Code of Canon Law, he wrote: "It has seemed most fitting to start from the Roman Curia so that, structured in a suitable way that everyone can understand, the Curia may more easily and effectively lend its help to the Roman Pontiff and the Church." Here are the principal effects of that reform: the Sacred Roman Rota, which had ceased to function in 1870, was reestablished to deal with judicial cases, while the Congregations lost their judicial competence and became purely administrative organs. The principle was also established whereby the Congregations would enjoy their own rights, deferring to nobody else, so that each individual matter was to be dealt with by its own dicastery, and not by several at the same time.

This reform by Pius X, later confirmed and completed in the Code of Canon Law promulgated in 1917 by our predecessor Benedict XV, remained practically unchanged until 1967, not long after the Second Vatican Council in which the Church delved more deeply into the mystery of its own being and gained a more lively vision of its mission.