Justin II (520-578) was the nephew of Emperor Justinian I and had supposedly been named his heir on the emperor's deathbed. Justin's early rule relied completely on the support of the aristocratic party, and faced with an empty treasury, he stopped paying off potential enemies as his uncle had done, leading to Avar invasions across the Danube river. Justin renewed conflict with the Sassanid Empire, refusing to pay tribute and making overtures with the Turks. However, he oversaw two disastrous campaigns that saw the Persians taking Syria and capturing the vitally important fortress of Dara. It was after these events that Justin reportedly lost his mind, falling into temporary bouts of insanity. Jusitn was advised by his wife Sophia to name a successor during his brief periods of sanity, choosing the general Tiberius over his own relatives in 574, adopting him as a son before withdrawing into retirement. He died four years later in 578, his insanity growing worse the whole time.