Nasrollah Pirnia , also known as Mirza Nasrollah Khan ( Persian : میرزا نصرالله خان نائینی ; 17 October 1840 – 13 September 1907, titled Moshir al-Dowleh ), was the first Iranian prime minister. He became Premier of Iran following the introduction of the Persian Constitution of 1906 , establishing Iran's first legitimate government approved by the Majlis on 7 October 1906. Before becoming prime minister, he had served as the minister of foreign affairs. He died in circumstances said to be suspicious and was buried in Imamzadeh Saleh of Tajrish .