Size of the College of Cardinals

The College of Cardinals, formerly styled the Sacred College of Cardinals, is the body of all cardinals of the Catholic Church. Its membership is 226, as of 28 June 2018.^[update] Most cardinals exit the College only by death, although a few leave it by election to the papacy, and still fewer leave by resignation or dismissal. Changes in life expectancy partly account for the increases in the size of the College.

Since the emergence of the College of Cardinals in the Early Middle Ages, the size of the body has historically been limited by popes, ecumenical councils, and even the College itself. From 1099 to 1986, the total number of cardinals was approximately 2,900 (excluding possible undocumented 12th century cardinals, cardinals appointed during the Western Schism by pontiffs now considered to be antipopes, and subject to some other sources of uncertainty), nearly half of which were created after 1655.

The word cardinal is derived from the Latin cardo, meaning "hinge". The office of cardinal as it is known today slowly evolved during the first millennium from the clergy of Rome. "The first time that the term cardinal appears in the Liber Pontificalis is in the biography of Pope Stephen III(IV) when in the Roman Synod of 769, it was decided that the Roman pontiff should be elected from among the deacons and cardinal priests."

In 845 the Council of Meaux "required Bishops to establish Cardinal titles or parishes in their towns and outlining districts." At the same time, the popes began referring to the cardinal priests of Rome to serves as legates and delegates within Rome at ceremonies, synods, councils, etc., as well as abroad on diplomatic missions and councils. Those who were assigned to the latter roles were given the titles of Legatus a latere (Cardinal Legate) and Missus Specialis (Special Missions).

During the pontificate of Stephen V (816-17), the three classes of the College that are present today began to form. Stephen decreed that all cardinal-bishops were bound to sing Mass on rotation at the high altar at St. Peter's Basilica, one per Sunday. The first class to form was that of the cardinal-deacons, direct theological descendants of the original seven ordained in Acts 6, followed by the cardinal-priests, and finally, the cardinal-bishops.

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