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.
Mehmed I
The reign of Mehmed I as sultan of the re-united empire lasted only eight years before his death, but he had also been the most powerful brother contending for the throne and "de facto" ruler of most of the empire for nearly the whole preceding period of 11 years of the Ottoman Interregnum that passed between his father's captivity at Ankara and his own final victory over his brother Musa Çelebi at the Battle of Çamurlu.
He was buried in Bursa, in a mausoleum erected by himself near the celebrated mosque which he built there, and which, because of its decorations of green glazed tiles, is called the Green Mosque. Mehmed I also completed another mosque in Bursa, which his grandfather Murad I had commenced but which had been neglected during the reign of Bayezid. Mehmed founded in the vicinity of his own Green Mosque and mausoleum two other characteristic institutions, one a school and one a refectory for the poor, both of which he endowed with royal munificence.