rupee. Rupee is today used as the national currency in India, Indonesia, Maldives, Mauritius, Nepal, Pakistan, Seychelles, Sri Lanka among other countries. Gold coins called the Mohur weighing 169 grains and copper coins called Paisa were also minted by his government. According to numismatists Goron and Goenka, it is clear from coins dated AH 945 (1538 AD) that Sher Khan had assumed the royal title of Farid al-Din Sher Shah and had coins struck in his own name even before the battle of Chausa. Sher Shah was responsible for greatly rebuilding and modernizing the Grand Trunk Road, a major artery which runs all the way from modern day Bangladesh to Afghanistan. Caravanserais (inns) and mosques were built and trees were planted along the entire stretch on both sides of the road to provide shade to travelers. Wells were also dug, especially along the western section. He also established an efficient postal system, with mail being carried by relays of horse riders. Sher Shah built several monuments including Rohtas Fort (now a UNESCO World Heritage Site in Pakistan), many structures in the Rohtasgarh Fort in Bihar, the Sher Shah Suri Masjid in Patna, the Qila-i-Kuhna mosque inside the Purana Qila complex in Delhi, and the Sher Mandal, an octagonal building also inside the Purana Qila complex, which later served as the library of Humayun. He built a new city, Bhera, in present-day Pakistan in 1545, including within it a grand masjid named after him. Sher Shah is generally viewed as tolerant of Hindus, except in the massacre following the surrender of Raisen. Tarikh-i-Sher Shahi (History of Sher Shah), written by Abbas Khan Sarwani, a waqia-navis under later Mughal Emperor, Akbar around 1580, provides a detailed documentation about Sher Shah's administration. Death and succession Sher Shah started the siege of Kalinjar in 1543 and was killed on 22 May 1545 during the siege of Kalinjar fort. When all tactics to subdue this fort failed, Sher Shah ordered the walls of the fort to be blown up with gunpowder, but he was seriously wounded as a result of the explosion of a mine when the Rajput garrison of the fort attacked his encampment at night. He was succeeded by his son, Jalal Khan, who then continued the siege and slaughtered the whole Rajput garrison of Kalinjar fort and took the title of Islam Shah Suri. His mausoleum, the Sher Shah Suri Tomb (122