Mohammad Sadegh, the Marvi historian, as a cultural and political character in the first half of Ghajari dynasty was considered as the Iran's contemporary historian. This was however, beside his order diplomatic careers, counseling and management of Homauun's office. Although, in Fathalishah's palace so many other historians were living, he was assigned by Shah as an official historian. However, he was regarded as the official historian and after his death his career was transferred to his son. Marvi historian was born in Marv. He started his education in his hometown, Mashhad, and then continued his education in Karbala and Najaf. He could enjoy learning Farsi literature and poetry with Ostad Soleiman Sabahi. He also got acquaintance with Fathalikhan Sabahi Kashani and with his help and his friend's, Muhammad Hossein Khan Marvi (son of Beiramalikhan Ghajar) who was also highly ranked in Fathalikhan's palace, he could be elected as the official secretary. It was due to his intelligence and insight that he was elected as historian, besides he started writing Jahanara history book. Marvi historian had a very great desire for poetry and literature and had written several books on literal and political issues. He wrote Jahanara book in several successive years, though he had decided to write one volume of the book every ten years. His first volume included the history of Pirshah Aghmuhammad Khan up to the year 1220 Hijri and second volume starts from the year 1220 Hijri to 1230 Hijri. Due to his multiple careers, the next volumes were not written and the second volume was never published. However these two volumes of Jahanara history book were succession to the Iranian history recordings from Safavid, Afsharid and Zandis and had a great effect on the historians of the Ghajari era. Although bias can be found in these books, the contemporary historians can use them for understanding the conditions of those eras.