 In 1467 , he took part in Matthias ' bitter defeat against Moldavia at the Battle of Baia . In 1476 , Corvinus decided to support Vlad III Dracula in reclaiming his Wallachian throne from Basarab Laiotă . He therefore made Báthory supreme commander over an army of 8 @,@ 000 infantry and 13 @,@ 000 cavalry , but since Báthory was rather inexperienced in military leadership , " the actual leadership was shared by Dracula and the Serbian despot Vuk <unk> . Before this , Dracula and Báthory had waged war in Bosnia , where Báthory was sent by Corvinus to free a certain Bosnian king whose name was also Matthias . The new campaign would involve Hungarian , Moldavian , and Wallachian troops , with the assistance of a small Serbian contingent . Dracula wrote to his cousin , Prince Stephen III of Moldavia , to wait for him so that the two could merge their armies , but the merging failed due to <unk> in movement of the Hungarian troops , which resulted in Stephen 's defeat at the Battle of Valea Albă on July 26 , 1476 . On August 18 , the two armies merged and helped Stephen get rid of the Turks in Moldavia . After a consultation that took place in the city of Braşov , Dracula , Báthory , and <unk> invaded Wallachia from southern Transylvania with an army of 35 @,@ 000 , whereas Stephen would aid them by attacking eastern Wallachia with 15 @,@ 000 men . Dracula 's offensive began in early November 1476 and defeated Laiotă 's 18 @,@ 000 strong army at Rucăr , at the Wallachian @-@ Transylvanian border . Both armies lost around 10 @,@ 000 men . 
