anti-pope Gregory VIII., who was in Rome. Soon after his consecration he
opened negotiations with the emperor with a view to settling the dispute
over investiture. Terms of peace were arranged, but at the last moment
difficulties arose and the treaty was abandoned; and in October 1119
both emperor and anti-pope were excommunicated at a synod held at Reims.
The journey of Calixtus to Rome early in 1120 was a triumphal march. He
was received with great enthusiasm in the city, while Gregory, having
fled to Sutri, was delivered into his hands and treated with great
ignominy. Through the efforts of some German princes negotiations
between pope and emperor were renewed, and the important Concordat of
Worms made in September 1122 was the result. This treaty, made possible
by concessions on either side, settled the investiture controversy, and
was confirmed by the Lateran council of March 1123. During his short
reign Calixtus strengthened the authority of the papacy in southern
Italy by military expeditions, and restored several buildings within the
city of Rome. During preparations for a crusade he died in Rome on the
13th or 14th of December 1124.

See M. Maurer, _Pabst Calixt II._ (Munich, 1889); U. Robert, _Hisloire
du pape Calixte II._ (Paris, 1891); and A. Hauck's _Realencyklopadie_,
Band iii. (Leipzig, 1897).

CALIXTUS III. (_c._1378-1458), pope from 1455 to 1458, was a Spaniard
named Alphonso de Borgia, or Borja. A native of Xativa, he gained a
great reputation as a jurist, becoming professor at Lerida; in 1429 he
was made bishop of Valencia, and in 1444 a cardinal, owing his promotion
mainly to his close friendship with Alphonso V., king of Aragon and
Sicily. Chosen pope in April 1455, he was very anxious to organize a
crusade against the Turks, and having sold many of his possessions,
succeeded in equipping a fleet. Neither the princes nor the people of
Europe, however, were enthusiastic in this cause, and very little result
came from the pope's exertions. During his papacy Calixtus became
involved in a quarrel with his former friend, Alphonso of Aragon, now
also king of Naples, and after the king's death in June 1458 he refused
to recognize his illegitimate son, Ferdinand, as king of Naples,
asserting that this kingdom was a fief of the Holy See. This pope was
notorious for nepotism, and was responsible for introducing his nephew,
Rodrigo Borgia, afterwards Pope Alexander VI., to Rome. He died on the
6th of A