After Alexander Aldea died in 1436, Vlad seized Wallachia with Hungarian support. Following the death of Sigismund of Luxembourg in 1437, Hungary's position weakened, causing Vlad to pay homage to Murad II, which included participating in Murad II's invasion of Transylvania in the summer of 1438. John Hunyadi, Voivode of Transylvania, came to Wallachia to convince Vlad to join a crusade against the Ottomans in 1441. After Hunyadi routed an Ottoman army in Transylvania, the sultan ordered Vlad to come to Edirne where he was captured in 1442. Hunyadi invaded Wallachia and made Vlad's cousin, Basarab II, voivode.