After Michael failed to respect the treaty, the Ottomans gave assistance to his rival, Dan, who crossed into Wallachia in 1420.

[1] Alexander Aldea and Vlad were Michael's most prominent illegitimate half-brothers, who, in accordance with local custom, could have claimed the throne of Wallachia.

[4] Michael supported Sigismund of Luxembourg, King of Hungary, who launched a campaign against the Ottoman Empire in the autumn of 1419.

[4][5] They captured the city of Turnu Severin that Michael's father had lost to the Ottomans, but it was put under Sigismund's control.

[5] In retaliation, the sultan broke into Wallachia, forcing Michael to cede Giurgiu and other fortresses on the Danube to the Ottomans and to pay the tribute he had failed to send during the previous three years.