Accession of Mehmed II in Edirne
Mehmed II was born on 30 March 1432, in Edirne, then the capital city of the Ottoman state. His father was Sultan Murad II (1404–51) and his mother Hüma Valide Hatun, born in the town of Devrekani, Kastamonu.
When Mehmed II was eleven years old he was sent to Amasya to govern and thus gain experience, per the custom of Ottoman rulers before his time. Sultan Murad II also sent a number of teachers for him to study under. This Islamic education had a great impact in moulding Mehmed's mindset and reinforcing his Muslim beliefs. He was influenced in his practice of Islamic epistemology by practitioners of science, particularly by his mentor, Molla Gürani, and he followed their approach. The influence of Akshamsaddin in Mehmed's life became predominant from a young age, especially in the imperative of fulfilling his Islamic duty to overthrow the Byzantine empire by conquering Constantinople.
After Murad II made peace with the Karamanids in Anatolia in August 1444, he abdicated the throne to his 12-year-old son Mehmed II.
In Mehmed II's first reign, he defeated the crusade led by John Hunyadi after the Hungarian incursions into his country broke the conditions of the truce Peace of Szeged. Cardinal Julian Cesarini, the representative of the Pope, had convinced the king of Hungary that breaking the truce with Muslims was not a betrayal.
At this time Mehmed II asked his father Murad II to reclaim the throne, but Murad II refused. Angry at his father, who had long since retired to a contemplative life in southwestern Anatolia, Mehmed II wrote, "If you are the Sultan, come and lead your armies. If I am the Sultan I hereby order you to come and lead my armies." It was only after receiving this letter that Murad II led the Ottoman army and won the Battle of Varna in 1444.
Murad II's return to the throne was forced by Çandarlı Halil Paşa, the grand vizier at the time, who was not fond of Mehmed II's rule, because Mehmed II's influential lala (royal teacher), Akshamsaddin, had a rivalry with Çandarlı.