Prince Sehzade Yusuf Izzeddin Effendi (10 October 1857 - 1 February 1916, Ottoman Turkish: یوسف عزالدین افندی) was the Son of Sultan Abdul Aziz and the Crown Prince of the Ottoman Empire from 1909 until his death. Prince Yusuf lived in obscurity from the time of his father's death in 1876 until the dethronement of his cousin, Sultan Abdul Hamid II in 1909. Under the Turkish constitution, Yusuf, the oldest Ottoman prince, became heir to his cousin, Mehmed V. Considered a modernizer and reformer, he apparently committed suicide on 1 February 1916. It was suspected at the time that he might have been murdered at the connivance of the powerful minister of war, Enver Pasha, with whom he had clashed.