After decades of inconclusive fighting, Emperor Maurice ended the Byzantine–Sasanian War of 572–591 by helping the exiled Sasanian prince Khosrow, the future Khosrow II, to regain his throne from the usurper Bahrām Chobin. In return the Sasanians ceded to the Byzantines parts of northeastern Mesopotamia, much of Persian Armenia and Caucasian Iberia, though the exact details are not clear. More importantly for the Byzantine economy, they no longer had to pay tribute to the Sasanians. Emperor Maurice then began new campaigns in the Balkans to stop incursions by the Slavs and Avars.