The inscription reads Farmayesh-e janab-e jalalat ma'ab aqay-e najafquli khan samsam al-saltana ilkhani 'Amal-e Baktiari 1335 (to the order of His Excellency, exalted in dignity, the master Najaf Quli Khan Samsam al-Saltana, the Chief of the Bakhtiari tribe).
Najaf Quli Khan Samsam al-Saltana (1267-150-1930) was the chief of the Bakhtiari tribe and the one who captured Isfahan in 1909 and made himself governor during the constitutional revolution. After the establishment of the constitution, he went to be part of the government in Teheran, immediately joining the cabinet. He held various ministerial posts and was prime minister a number of times. (Bamdad, M.: Dictionary of National Biography of Iran, Vol.4, Teheran, 1966, pp.321-2).