Classical Age of the Ottoman Empire
Expansion continued during the first half of the reign of Suleiman I (r. 1520-1566), who conquered first Belgrade (1521) and Rhodes, before invading Hungary in 1526, defeating and killing King Louis II in the Battle of Mohács and briefly occupying Buda. Lacking a king, Hungary descended into civil war over the succession, and the Ottomans gave support to John Zápolya as a vassal prince. When their rivals the Habsburgs began to achieve the upper hand, Suleiman directly intervened by again conquering Buda and annexing it to the empire in 1541. Elsewhere, Suleiman led major campaigns against Safavid Iran, conquering Baghdad in 1534 and annexing Iraq. Ottoman rule was further extended with the incorporation of much of North Africa, the conquest of coastal Yemen in 1538, and the subsequent annexation of the interior.
Safavid dynasty
Humayun was not the only royal figure to seek refuge at Tahmasp's court. A dispute arose in the Ottoman Empire over who was to succeed the aged Suleiman the Magnificent. Suleiman's favourite wife, Hürrem Sultan, was eager for her son, Selim, to become the next sultan. But Selim was an alcoholic and Hürrem's other son, Bayezid, had shown far greater military ability. The two princes quarrelled and eventually Bayezid rebelled against his father. His letter of remorse never reached Suleiman, and he was forced to flee abroad to avoid execution. In 1559 Bayezid arrived in Iran where Tahmasp gave him a warm welcome. Suleiman was eager to negotiate his son's return, but Tahmasp rejected his promises and threats until, in 1561, Suleiman compromised with him. In September of that year, Tahmasp and Bayezid were enjoying a banquet at Tabriz when Tahmasp suddenly pretended he had received news that the Ottoman prince was engaged in a plot against his life. An angry mob gathered and Tahmasp had Bayezid put into custody, alleging it was for his own safety. Tahmasp then handed the prince over to the Ottoman ambassador. Shortly afterwards, Bayezid was killed by agents sent by his own father.