Short answers, pulled from the story.
Sher Shah Suri, born Farid al-Din Khan, was the Sultan of Hindustan and founder of the Sur Empire, ruling from 1540 until his death on the 22nd of May 1545. He defeated the Mughal Emperor Humayun at the Battle of Chausa and again at Kannauj to claim the throne, and his empire covered nearly all of Northern India by the end of his reign.
Sher Shah Suri standardized the silver rupee as a coin of 178 grains, the direct precursor of the modern rupee used today in India, Pakistan, Nepal, Sri Lanka, and several other countries. He also rebuilt the Grand Trunk Road from Chittagong to Kabul, established a postal relay system, abolished interprovincial customs duties, and reorganized imperial administration into Iqtas, Sarkars, and Parganas.
Sher Shah Suri defeated Humayun at the Battle of Chausa, routing a Mughal army reportedly 200,000 strong and inflicting over 7,000 casualties. He then defeated Humayun again at Kannauj, forcing the Mughal emperor to flee India. Sher Shah was crowned Sultan of Hindustan for the second time on the 17th of May 1540.
Sher Shah Suri died on the 22nd of May 1545 from wounds sustained during the siege of Kalinjar Fort. Accounts vary; one states a cannon burst wounded him mortally, another describes a bomb falling back from a rampart and igniting a cache of explosives, leaving him half-burned. He survived two days in his tent before dying, having reportedly insisted on continuing the assault even in critical condition.
Sher Shah Suri is buried in his mausoleum at Sasaram, Bihar, which stands in the middle of an artificial lake. Construction of the tomb was completed on the 16th of August 1545, three months after his death. British archaeologist Cunningham considered it among the finest monuments in India.
After Sher Shah's death, succession disputes fractured the empire. His designated heir Adil Khan was passed over by the nobility in favor of Jalal Khan, who ruled as Islam Shah Suri until 1553. His successor Firuz Shah Suri was then assassinated by a nephew, Muhammad Adil Shah, triggering a civil war that allowed Humayun to retake Delhi and re-establish Mughal rule.