After the 1913 coup and Mahmud Şevket Pasha's assassination, the Empire was ruled by the CUP in a dictatorship, whose leaders were the triumvirate of Talaat, İsmail Enver, and Ahmed Cemal (known as the Three Pashas), of whom Talaat was politically most powerful. Talaat and Enver Pasha were influential bringing the Ottoman Empire into the First World War. During World War I, Talaat as Interior Minister on 24 April 1915 the arrest and deportation of Armenian intellectuals in Constantinople (now Istanbul), most of them being ultimately murdered, and on 30 May 1915 requested the Tehcir Law (Temporary Deportation Law); these events initiated the Armenian genocide. He is widely considered the main perpetrator of the genocide, and is thus held responsible for the death of around 1 million Armenians. Talaat Pasha became Grand Vizier (Prime Minister) in 1917 and oversaw the introduction of many modernizing social reforms, which Mustafa Kemal Atatürk would later build upon.