Eldest son of Hasan Khan, an Afghan noble of the Sur tribe Farid Khan was born around 1489. Hasan Khan's father Ibrahim Khan, a horse-dealer according to Abul Fazl, was among the soldiers recruited by Sultan Bahlul Lodi from Roh, the highlands of the Sulaiman range, and had held assignment for the maintenance of his followers, first in the Punjab but afterwards in the Pargana of Narnaul (Hissar) under the Afghan chief Jamal Khan. Hasan Khan succeeded him. When Jamal Khan was transferred by Sultan Sikander Lodi to Jaunpur, he took the Suris with him and Hasan Khan received the Parganas of Sasaram, Hajipur and Khavasspur Tanda for the maintenance of 500 horses.
Due to domestic conflict arising out of the jealousy of his step-mother, Farid left Sasaram for Jaunpur to pursue his studies and to serve under Jamal Khan. His father called him back and placed him in charge of the two other Parganas, when he had his first experience in administration. He mastered the revenue system and the customary law and suppressed bribery, extortion, brigandage and disaffection. Influenced by his step-mother, Hasan divested him in favour of his step-brother Sulaiman. Farid went to Agra and sought service with Daulat Khan, a Commander of 12,000 horses, under Sultan Ibrahim Lodi. He helped Farid obtain a royal grant in succession to his father. Farid took charge and his step-brother sought refuge with Mohammed Khan Sur of Chainpur.
Meanwhile Babur invaded India and defeated and killed Ibrahim Lodi. Bihar Khan Lohani, the Governor of Bihar, declared independence and assumed the title of Sultan Muhammed. Farid joined him and soon rose to high rank. One day while hunting with him, he slew a tiger and received the title of Sher Khan. Sultan Muhammad appointed him tutor to his son Jalal Khan. However, Muhammad Khan Sur, with the Sultan's authority, again sought to play his brother against Sher Khan who took the help of Junaid, the governor of Kara and Manikpur. Sher Khan not only received his assignment but expelled Mohammed Sur from Chainpur into Rohtas Hills. This attracted Afghan soldiers to his banner. With characteristic statesmanship, he now sought reconciliation with Mohammed Sur and restored him to Chainpur.
Sher Khan then visited Junaid at Agra and was presented to Babur. He entered Babur's service with the object of studying his system in order to plan his expulsion from India and accompanied him on his expedition to Chanderi but soon he aroused Babur's anger and suspicion and left for Sasaram. From now onwards Farid tried to unite the Afghans against the Mughals. He rejoined Sultan Muhammad. On his death, Jalal Khan being still a minor, his mother, who became the regent, appointed Sher Khan as her agent. Sher Khan thus became the de-facto ruler of Bihar.
Sher Khan now desired to unite Bengal and Bihar but Sultan Muhammad of Bengal invaded Bihar and was defeated by Sher Khan. But Jalal Khan and the majority of the Lohanis began plotting against him and he was ordered to return to Sasaram. When another attack came, Jalal Khan accepted the Sultan of Bengal as his sovereign. Sher Khan took advantage of this, raised the banner of revolt, and routed the royal army. Sher Khan became the sovereign of Bihar.
Sher Khan then took Chunar fortress. But he was summoned by Mahmud Lodi, the brother of Ibrahim, who had settled in Patna and assumed royal estate. Sher Khan agreed to help Lodi conquer Oudh and helped him take Jaunpur and Lucknow. Humayun rushed down from Agra and compelled Mahmud to retire into Bihar and demanded surrender of Chunar from Sher Khan in token of allegiance. Sher Khan refused but on call from Gujrat Humayun changed course and set out for Gujarat taking his son Qutb Khan as hostage.
Sher Khan then Consolidated his power in Bihar and Bengal and defeated Sultan Mahmud of Bengal who took refuge with Humayun. Sher Khan took Rohtas from Raja Churaman. He took Benares, Jaunpur, Sambhal and Bahraich and threatened to march on Agra. At the battle of Chausa on 26 June, 1539 Humayun was defeated and fled to Agra. Sher Khan assumed the royal title of Fariduddin Sher Shah, struck coin and caused the Khutba to be recited in his name. He followed Humayun towards Agra, occupied Kanauj and Kalpi and sought alliance with the Sultans of Malwa and Gujarat. His next & final encounter with Humayun was on 17 May, 1540. Humayun sustained a crushing defeat. Sher Shah pursued Humayun to Agra, to Lahore and into Sind. Sher Shah had become the Emperor of Hindustan.
In 1541, Sher Shah crushed a rebellion in Bengal and reorganised the administration. In 1542, he annexed Malwa. On his way back, he took Ranthambhor. In 1543, Sher Shah marched to Raisen to punish Raja Puran Mal who had taken Chanderi and put its inhabitants to the sword. Puran Mal's forces were massacred by Sher Shah, the deed which has left the deepest blot on his memory. In 1543, Sher Shah defeated Maldeo Rathor of Marwar and then took Chittor and laid siege on Kalanjir. There he suffered burns from a rocket explosion and died on 22 May 1545.
The greatest of the Muslim rulers of India and entirely free from, and active in the correction of, the faults usually associated with his race, in his youth, he acquired learning and studied the arts of Government, and put his knowledge into practice in administering his ancestral jagirs. He devoted himself wholly to the affairs of the State, allowed himself no leisure and was personally acquainted with all ‘details of civil administration as no other Indian ruler, before or since, has been.’
Sher Shah reorganised the land revenue system to ensure due collection as well as to prevent oppression of cultivators.
Sher Shah’s army administration was highly efficient. He reintroduced branding of horses.
Sher Shah built roads and highways from Sonargaon to the Indus, from Agra to Mandu, from Agra to Chittor and from Lahore to Multan, lined them with trees and with caravanserais and places of worship at regular intervals. He introduced the system of horse-post. He extended the city of Delhi and built two forts there as well as the famous fortress of Rohtas on the Jhelum.
Sher Shah’s greatest achievement was to forge the Afghan tribes into a ruling elite and transform a tribal confederacy into a State. For the only time in history, an Afghan established and ruled an Afghan kingdom in which none was for a party and all were for the state.
From a petty assigence, Sher Shah rose to become an emperor who left a deep impression on the country he ruled for only 5 years.
Under his rule, crime was suppressed, there was peace in the country and law and order was maintained; justice was promptly administered.
A pious and orthodox Muslim, he was liberal and tolerant, adopted, as his state policy, the principle of non-discrimination on the basis of religion. He was indeed the forerunner of the modern secular state. (Source: Cambridge History of India)