The expansion of the Ottoman Empire reached the Danube around 1390. The Ottomans invaded Wallachia in 1390 and occupied Dobruja in 1395. Wallachia paid tribute to the Ottomans for the first time in 1417, Moldavia in 1456. However, the two principalities were not annexed, their princes were only required to assist the Ottomans in their military campaigns. The most outstanding 15th-century Romanian monarchs – Vlad the Impaler of Wallachia and Stephen the Great of Moldavia – were even able to defeat the Ottomans in major battles. In Dobruja, which was included in the Silistra Eyalet, Nogai Tatars settled and the local Gypsy tribes converted to Islam. The disintegration of the Kingdom of Hungary started with the Battle of Mohács on 29 August 1526. The Ottomans annihilated the royal army and Louis II of Hungary perished. By 1541, the entire Balkan peninsula and northern Hungary became Ottoman provinces. Moldavia, Wallachia, and Transylvania came under Ottoman suzerainty but remained fully autonomous and until the 18th century, had some internal independence.