During the period of the Nizams' rule, Hyderabad became wealthy - thanks to the Golconda mines which were the 'only sources of diamonds in the world market at that time (apart from South African mines) making the 7th Nizam the richest person in the world. Osman Ali Khan, Asaf Jah VII and his family including Salar Jung I were taught by Nawab Sarwar Ul Mulk and Agha Mirza Baig Bahadur, who was his political advisor, and the senior-most salute state among the Indian princely states. It was spread over in the Deccan, ruled by the Asaf Jahi dynasty. The Nizams were conferred with the title of His Exalted Highness, and "Faithful Ally of the British Government" for their roles in the Second and Third Anglo-Mysore Wars and the Indian Rebellion of 1857, becoming the only Indian prince to be given both these titles.