[44] Henceforward the history of the Caliphate is largely that of the
Seljuk princes (see SELJUKS).

CALIVER, a firearm used in the 16th century. The word is an English
corruption of "calibre," and arises from the "arquebus of calibre," that
is, of standard bore, which replaced the older arquebus. "Caliver,"
therefore, is practically synonymous with "arquebus." The heavier
musket, fired from a rest, replaced the caliver or arquebus towards the
close of the century.

CALIXTUS, or CALLISTUS, the name of three popes.

CALIXTUS I., pope from 217 to 222, was little known before the discovery
of the book of the _Philosophumena_. From this work, which is in part a
pamphlet directed against him, we learn that Calixtus was originally a
slave and engaged in banking. Falling on evil times, he was brought into
collision with the Jews, who denounced him as a Christian and procured
his exile to Sardinia. On his return from exile he was pensioned by Pope
Victor, and, later, was associated by Pope Zephyrinus in the government
of the Roman church. On the death of Zephyrinus (217) he was elected in
his place and occupied the papal chair for five years. His theological
adversary Hippolytus, the author of the _Philosophumena_, accused him of
having favoured the medalist or Patripassian doctrines both before and
after his election. Calixtus, however, condemned Sabellius, the most
prominent champion of that system. Hippolytus accused him also of
certain relaxations of discipline. It appears that Calixtus reduced the
penitential severities applied until his time to those guilty of
adultery and other analogous sins. Under Calixtus and his two immediate
successors, Hippolytus was the leader of a schismatic group, organized
by way of protest against the election of Calixtus. Calixtus died in
222, in circumstances obscured by legends. In the time of Constantine
the Roman church reckoned him officially among the martyr popes.
(L. D.*)

CALIXTUS II. (d. 1124), pope from 1119 to 1124, was Guido, a member of a
noble Burgundian family, who became archbishop of Vienne about 1088, and
belonged to the party which favoured reform in the Church. In September
1112, after Pope Paschal II. had made a surrender to the emperor Henry
V., Guido called a council at Vienne, which declared against lay
investiture, and excommunicated Henry. In February 1119 he was chosen
pope at Cluny in succession to Gelasius II., and in opposition to the