Nasser-ad-din Shah's elder son, Massud Mirza Zil-os-Sultan was one the most powerful and one of the richest figures of his time. He was governor of Isfahan for thirty five successive years, and on the whole he was governor of Mazandaran, Fars, and Isfahan for forty years alternately. He was for a time the absolute ruler of seventeen cities of the country.
He was born about 1849. He was three years older than Mozaffar-ad-din Shah. As his mother, Effat-os-Saltaneh was not a Qajar princess or one of Nasser-ad-din Shah's formal wives; he was not chosen crown prince. From his childhood, he envied his brother Mozaffaraddin Mirza, and his wish to become a king did not leave him until the rest of his life.
When he was thirteen, he was appointed the governor of Mazandaran, Turkman Sahra, Semnan, and Damghan for four years.
Then he was recalled to Tehran, married Hamdam-ol-Moluk (later Hamdam-os-Saltaneh and Amir Kabir's daughter) and proceeded to Shiraz as governor of the province. He went to Isfahan in 1873, and ruled there for thirty five successive years up to 1908. From his early youth, he embarked on gathering wealth including properties, jewelries and etc. His tenure of office was mostly passed in the suppression of opposition and adding to his wealth and encroaching upon people's rights to the point the administration of the country had no place in his mind. However it should be noted that establishment of regular army, founding Farhang newspaper, opening of modern royal school and ecole de militaire for volunteers are among his achievements in Isfahan.