Cardinal (Lat. cardinalis, principal or chief), originally, any clergyman bearing an official appointment in a principal church. By degrees, however, the title became the exclusive designation of the principal clergy of the Roman church, who, as the natural counsellors of the pope, acquired an influence and consideration of a superior kind. Thus, in process of time, an ecclesiastical senate was formed to advise and assist the sovereign pontiff in the government of the church; and the constitution of this body was continually perfected until it was ultimately fixed in its present form by Pope Sixtus V. (1585-'90). The dignity of cardinal is the highest in the Latin church after that of pope, who is elected by the assembled body of cardinals. (See Conclave.) Cardinals have also the rank of secular princes, being classed with electors, and next after kings. Their insignia (besides those worn by bishops, which all cardinals, even those who are not in sacred orders, are entitled to use) are a purple mantle, a scarlet hat, and a ring of sapphire set in gold.

They are divided into three classes, cardinal bishops, cardinal priests, and cardinal deacons; and the maximum number of these classes is respectively 6, 50, and 14. The first class, when full, consists of the bishops of the six suffragan sees of the former States of the Church, Ostia, Porto, Albano, Tusculum, Sabina, and Palestrina. Their title arose from the circumstance that they were obliged to officiate pon-tifically on certain days in the greater basilicas of Rome, and were inaugurated or incardinated (incardinati) into these functions, and hence ranked as the chief of the cardinals, who were, as stated above, the clergy of these principal churches. The cardinal priests were originally the arch priests who presided over the clergy attached to the principal churches, of which there were already 25 at the close of the 5th century. The cardinal deacons sprung from the regionary deacons, of whom there were originally 7 and afterward 14, each one having charge over the poor in a certain district of the city. In modern times the cardinal priests are very frequently archbishops and bishops. Each one, however, derives his title from a particular church, and in that church he has special jurisdiction. The cardinal deacons may be priests, deacons, or subdeacons or merely in minor orders.

They are generally men who have devoted their lives to the study of law, diplomacy, and statesmanship, and are employed in the temporal affairs of the Roman court. Every cardinal, whatever order he may have received, exercises quasi-episcopal jurisdiction in his church, gives solemn benediction, and issues dispensations. Those who are priests can give the tonsure and minor orders. They take precedence of all prelates, even patriarchs, and have a decisive voice in general councils. The appointment of a cardinal rests exclusively with the pope. The number is never quite filled, and there are always some reserved in petto, to be announced when a death occurs or any other suitable opportunity presents itself. In accordance with stipulations entered into at different times, the pope appoints a few cardinals recommended by the principal Catholic sovereigns, who are called crown cardinals. The decrees of the council of Trent and the constitutions of Sixtus V. direct that the cardinals should be selected as far as possible from all nations.

The reasons of this direction are evident; for, as the pope exercises supreme authority over so many national churches in different parts of the world, he needs the advice of wise and learned men from all civilized countries in order to give a truly catholic character to his administration. On Jan. 1, 1873, there were 47 cardinals, leaving 23 vacancies. There were 4 cardinal bishops, all born in Italy; 36 cardinal priests, of whom 25 were born in Italy, 5 in France, 3 in Germany, 1 in Spain, 1 in Ireland, and 1 in Guatemala; and 7 cardinal deacons, all born in Italy. Of these 47 cardinals, 38 were appointed by Pope Pius IX. The oldest was the cardinal priest Alexander Biliet, archbishop of Chambery, born in 1783, appointed in 1861; the youngest, the cardinal priest Lucien Bonaparte, born in 1828, appointed in 1868. There were 19 more than 70 years of age, 19 between 60 and 70, 5 between 50 and 60, and 4 between 40 and 50.