Sher Shah Suri (1472, or 1486 – 22 May 1545), born Farīd Khān, was the founder of the Sur Empire in India, with its capital in Sasaram in modern-day Bihar. He standardized the silver coin to the weight of 178 grams and named the currency as rupee based on the ancient Sanskrit term for silver. Sher Shah took control of the Mughal Empire in 1540 CE. After his accidental death in 1545 CE, his son Islam Shah became his successor. He first served as a private before rising to become a commander in the Mughal army under Babur and then the governor of Bihar. In 1537, when Babur's son Humayun was elsewhere on an expedition, Sher Shah overran the state of Bengal and established the Suri dynasty. A brilliant strategist, Sher Shah proved himself as a gifted administrator as well as a capable general. His reorganization of the empire laid the foundations for the later Mughal emperors, notably Akbar, son of Humayun. During his five-year rule from 1540 to 1545, he set up a new economic and military administration, issued the first Rupiya from "Tanka" and organized the postal system of the Indian Subcontinent. Some of his strategies and contributions were later idolized by the Mughal emperors, most notably Akbar. Suri further developed Humayun's Dina-panah city and named it Shergarh and revived the historical city of Pataliputra, which had been in decline since the 7th century CE, as Patna. He extended the Grand Trunk Road from Chittagong in the frontiers of the province of Bengal in northeast India to Kabul in Afghanistan in the far northwest of the country. The influence of his innovations and reforms extended far beyond his brief reign; his arch foe, Humayun, referred to him as “Ustad-I-Badshahan”, teacher of kings. In the seven years of his reign he never lost a battle. Early life and origin His grandfather Ibrahim Khan Sur, who started out as a horse trader, became a landlord (Jagirdar) in Narnaul area (present-day Haryana), representing his patron Jamal Khan Lodi Sarangkhani, who assigned him a few villages in Hissar. Sikandar Lodi appointed Sarangkhani, who supported Sikandar's struggle to the throne, as governor of Jaunpur area (present-day Uttar Pradesh) after its conquest. Jamal's son and successor Khan-i-Azam Ahmad Khan Sarangkhani, with a rank of 20,000 sawars, further appointed Ibrahim Sur's son Hasan, a leader of Afghan freebooters, to the iqta of Sasaram and Khawaspur-Thanda