In 530 a major Persian offensive in Mesopotamia was defeated by Roman forces under Belisarius at Dara, while a second Persian thrust in the Caucasus was defeated by Sittas at Satala. Belisarius was defeated by Persian and Lakhmid forces at the Battle of Callinicum in 531, which resulted in his dismissal. In the same year the Romans gained some forts in Armenia, while the Persians had captured two forts in eastern Lazica. Immediately after the Battle of Callinicum unsuccessful negotiations between Justinian's envoy, Hermogenes, and Kavadh took place. A Persian siege of Martyropolis was interrupted by Kavadh I's death and the new Persian king, Khosrau I, re-opened talks in spring 532 and finally signed the Perpetual Peace in September 532, which lasted less than eight years. Both powers agreed to return all occupied territories, and the Romans agreed to make a one-time payment of 110 "centenaria" (11,000 lb of gold). The Romans recovered the Lazic forts, Iberia remained in Persian hands, and the Iberians who had left their country were given the choice of remaining in Roman territory or returning to their native land.