Neighboring states were alarmed by this upsetting of the balance of power, especially the Hungarian nobility in Transylvania, who rose against Michael in rebellion. With the help of Basta, they defeated Michael at the Battle of Mirăslău, forcing the prince to leave Transylvania together with his remaining loyal troops. A Polish army led by Jan Zamoyski drove the Wallachians from Moldavia and defeated Michael at Năieni, Ceptura, and Bucov (Battle of the Teleajăn River). The Polish army also entered eastern Wallachia and established Simion Movilă as ruler. Forces loyal to Michael remained only in Oltenia.