Tiberius II Constantine (; ; died 14 August 582) was Eastern Roman emperor from 574 to 582. Tiberius rose to power in 574 when Justin II, prior to a mental breakdown, proclaimed him caesar and adopted him as his own son. In 578, the dying Justin II gave him the title of augustus, thus becoming co-emperor alongside him. Tiberius became sole ruler less than two weeks later, assuming the regnal name of "Constantine" under which he reigned until his death. Early career Born in Thrace in the mid-6th century, Tiberius was appointed to the post of notarius. There, sometime after 552, he was introduced by the Patriarch Eutychius to the future emperor, Justin II, with whom he became firm friends. Under Justin's patronage, Tiberius was promoted to the position of Comes excubitorum, which he held from approximately 565 through to 574. He was present during Justin's imperial accession on 14 November 565 and also attended his inauguration as consul on 1 January 566. Justin ceased making payments to the Avars, which had been implemented by his predecessor, Justinian. In 569, he appointed Tiberius to the post of Magister utriusque militiae, with instructions to deal with the Avars and their demands. After a series of negotiations, Tiberius agreed to allow the Avars to settle on Roman territory in the Balkans, in exchange for male hostages taken from various Avar chiefs. Justin, however, rejected the agreement, insisting on taking hostages from the family of the Avar Khan himself. That condition was rejected by the Avars and so Tiberius mobilized for war. Avar War of 570 In 570, he defeated an Avar army in Thrace and returned to Constantinople. While attempting to follow up that victory in late 570 or early 571, Tiberius was defeated in a battle in which he narrowly escaped death, as his army was fleeing the battlefield. Agreeing to a truce, Tiberius provided an escort to the Avar envoys to discuss the terms of a treaty with Justin. On their return, the Avar envoys were attacked and robbed by local tribesmen, prompting them to appeal to Tiberius for help. He tracked down the group responsible and returned the stolen goods. In 574, Justin had a mental breakdown, forcing Empress Sophia to turn to Tiberius to manage the empire, which was fighting the Persians to the east and dealing with the internal crisis of the plague. To achieve a measure