Saxon town of Sighișoara (then in the Kingdom of Hungary), where his father lived in a three-story stone house from 1431 to 1435. Modern historians identify Vlad's mother either as a daughter or kinswoman of Alexander I of Moldavia or as his father's unknown first wife. Vlad II Dracul seized Wallachia after the death of his half-brother Alexander I Aldea in 1436. One of his charters (which was issued on 20January 1437) preserves the first reference to Vlad III and his elder brother, Mircea, mentioning them as their father's "firstborn sons". They were mentioned in four further documents between 1437 and 1439. The last of the four charters also refers to their younger brother, Radu. After a meeting with John Hunyadi, Voivode of Transylvania, Vlad II Dracul did not support an Ottoman invasion of Transylvania in March 1442. The Ottoman Sultan, Murad II, ordered him to come to Gallipoli to demonstrate his loyalty. Vlad and Radu accompanied their father to the Ottoman Empire, where they were all imprisoned. Vlad Dracul was released before the end of the year, but Vlad and Radu remained hostages to secure his loyalty. They were held imprisoned in the fortress of Eğrigöz (now Doğrugöz), according to contemporaneous Ottoman chronicles. Their lives were especially in danger after their father supported Vladislaus, King of Poland and Hungary, against the Ottoman Empire during the Crusade of Varna in 1444. Vlad II Dracul was convinced that his two sons would be "butchered for the sake of Christian peace," but neither Vlad nor Radu was murdered or mutilated after their father's rebellion. Vlad Dracul again acknowledged the sultan's suzerainty and promised to pay a yearly tribute to him in 1446 or 1447. John Hunyadi (who had by then become the regent-governor of Hungary in 1446), invaded Wallachia in November 1447. The Byzantine historian Michael Critobulus wrote that Vlad and Radu fled to the Ottoman Empire, which suggests that the sultan had allowed them to return to Wallachia after their father paid homage to him. Vlad Dracul and his eldest son, Mircea, were murdered. Hunyadi made Vladislav II (son of Vlad Dracul's cousin, Dan II) the ruler of Wallachia. Reigns First rule Upon the death of his father and elder brother, Vlad became a potential claimant to Wallachia. VladislavII of Wallachia accompanied John Hunyadi, who launched a campaign against the Ottoman Empire in September 1448. Taking advantage of his opponent's absence,