Alexander Aldea went to Adrianople to do homage to the Ottoman Sultan, Murad II, in 1432. Vlad wanted to invade Wallachia with the support of Wallachian boyars (or noblemen) who had fled to Transylvania, but Alexander Aldea's principal official, Albu, prevented the invasion. Sigismund authorized Vlad to buy weapons and muster an army of exiled boyars only in 1434. In 1435, Alexander Aldea fell seriously ill and never recovered. Taking advantage of his brother's illness, Vlad broke into Wallachia, but Alexander Aldea and his Ottoman allies forced him to retreat.