Çankiri (correct Turkish spelling Çankırı) is a town in Turkey, in Çankırı Province, about 140 km northeast of Ankara. It is situated in a rich well-watered valley, at about 800 m (2500 ft) in elevation.

It was anciently named Gangra, then Germanicopolis for a period, then Changra, Kandari, or Kanghari.

Gangra, the capital of the Paphlagonian kingdom of Deiotarus Philadelphus , son of Castor, was taken into the Roman province of Galatia on his death in 65 BC. The earlier town, the name of which signified she-goat, was built on the hill behind the modern city, on which are the ruins of a late fortress; while the Roman city occupied the site of the modern. It was named Germanicopolis, after the emperor Claudius, until the time of Caracalla.

In Christian times Gangra was the metropolitan see of Paphlagonia. In the 4th century the town was the scene of an important ecclesiastical synod, the Synod of Gangra . Conjectures as to the date of this synod vary from 341 to 376. All that can, be affirmed with certainty is that it was held about the middle of the 4th century. The synodal letter states that twenty-one bishops assembled to take action concerning Eustathius (of Sebaste?) and his followers, who condemned marriage, disparaged the offices of the church, held conventicles of their own, wore a peculiar dress, denounced riches, and affected especial sanctity. The synod condemned the Eustathian practices, declaring however, with remarkable moderation, that it was not virginity that was condemned, but the dishonouring of marriage; not poverty, but the disparagement of honest and benevolent wealth; not asceticism, but spiritual pride; not individual piety, but dishonouring the house of God. The twenty canons of Gangra were declared ecumenical by the council of Chalcedon, 451.

See Mansi ii. pp. 1095-1122; T-!ardoujn i. pp. 530-540; Hefele 2nd ed., i. pp. 777 sqq. (English trans. ii. pp. 325 sqq.).