Nasir-ud-din-Mahmud was just a nominal King; the real power was in the hands of Ghiyas-ud-din Balban, a slave of Iltutmish, who belonged to the Ilabari tribe of the Turks.
The Slave and the Bhisti
He was captured by Mongols in his childhood and was brought to India. Iltutmish had bought him in 1232. At first, Sultan refused to buy him because of his shortness and ugliness, but Balban begged him to buy him and he was bought and placed among the Bhistis (water bearers).
The Huntsman and the Noble
But Balban was fit for other better jobs. In due course of time he was enrolled in the "Corp of Forty", served Raziya has her chief huntsman, retained his post under Baharam. When Baharam was removed, Balban was a rebel, later getting the governorship of Hansi.
The General and Minister
The feeble successors of Iltutmish invited frequent rebels among the Hindus and Balban had dedicated his energy in leading his troops through Doab, Ranthambore, Malwa, Kalinjar etc. He became too powerful that Nasiruddin, prejudiced against his achievements and had banished him from the court, but he was later taken back and returned all his honors. He served his sultan Nasir-ud-din Mahmud for 20 years indefatigably and overcame all the rebellions, plots, conspiracies and frequent Mongol Alarms.
Nasir-ud-din Mahmud was a religious person. He lived a life of Darvesh, spending his time in copying the Holy Koran, and had no female servants, mistresses etc. He was actually not worthy of becoming the 13th century Sultan of India, but it was Balban who could fill his space and care for the Government.
But it was not an easy task. Years after years, the rebels of Hindus as well as plots and counter plots of the Turkish chiefs wanted a strong man to keep in check and Balban's opulent energy was able to do this task. He became the Sardar of the Nobles.
Overtaking the powers of Chihalgani showed distant results. Now Sultan was important and not the "Corp of Forty".
The Impeccable Sultan
Death of his master Nasir-ud-din Mahmud was followed by his natural ascending on the throne. The impeccable King in Balban subdued all the rebel forces with a iron hand and pounced upon the disturbing placed like a lion and killed the rebels without mercy. He was terribly severe towards the officers, executing them without mercy.
Crushing the Mewatis
The power of the Mewatis in the outskirts of Delhi was so dreadful that the gates of the city were closed in the evening after the evening Namaz. It is documented that Balban crushed the infidel Mewatis and ordered clearing the forests. The jungles were cleared and everyone who came in the way was killed taking the toll to 100 thousand. The dacoits in the Doab region were dealt with Iron hand.
Reorganization of army
To counter the Mongols, he organized and disciplined his army to the Highest point of efficiency. He refused to entrust any authority to Hindus.
Revolt of Tughril Khan in Bengal:
The Bengal rulers were a great headache to the Delhi Government. The local governors declared their independence whenever there was a chaos at Delhi. In 1279, the subedar of Bengal Tugril Khan neglected the aging Sultan of Delhi and declared his independence. The irritated Sultan sent a Big army under Aziz Khan, but he was defeated by Tugril Khan. Aziz Khan fled away. Balban send another army , which met with no better faith.
Now, the Sultan himself led a bigger army to Bengal. Hearing about Balban's march towards Bengal, Tugril Khan fled from the capital Lakhnauti and hid himself in forests. He was searched, tortured and killed. A mass killing at Lakhnauti was ordered and all the sympathizers of Tugril Khan were killed. The Bengal's affairs were now given to Balban's second son Bugara Khan and Sultan returned back to Delhi after suppressing this revolt. Bugara Khan and five of his descendents ruled Bengal for next 5 decades.
Death, Legacy and succession
Balban died in 1287, after 20 years of rule as a general & Minister and 20 years as a Sultan of Delhi.
Balban was the first king who understood the conditions and requirements of being a Sultan of Delhi and fulfilled them practically. He is known as one of the severest kings of India.
He introduced "Zaminbosi" of "Practice of Sijda", the people would Kneel down and touch the ground with their head to greet the Sultan.
He forwarded the Iranian Theory of Divine Rights, that Sultan is the representative of God on Earth.
He executed the "Corp of Forty" and ended its influence.
To counter the Mongols, he organized his military. For this he made some changes like abolition of the post of the Naik and creating a new department of military affairs known as Diwan-i-arz. The in charge of Diwan-i-arz was Ariz-i-Mumalik.
He kept Hindus away from army or other authorities.
He instructed the Ulemas to confine themselves to the religious affairs only.
Balban had destroyed the powerful group of slaves called "Chihalagani" who were true inheritors of Iltutmish. His hopes for his own succession were focused around his eldest son who died before him. His second son, Bugara Khan, who was governor of Bengal, was offered the throne but Bugara Khan preferred to stay at Bengal. In irritation, Balban left the throne to his deceased son's son named Kaikubad, a young lad of 17 years as his heir apparent.
After his death in 1287, Kaikubad was "placed" on the throne. Kaikubad, the young chap was carefully brought up under his grandfather. He was never allowed to see the young girls and enjoy the wine. This young man had been taught of all the good things and none of the bad things. All of a sudden, he found himself as master of India and now everything his youth desired was available to him.
The result was that he indulged in so much of drinking and debauchery, that he found himself struck with paralysis. When a mercenarily was sent to kill him, he was found in his bedroom in a lovely Sheesh Mahal (palace of mirrors) at Kilughari, a few miles from Delhi at the Bank of River Yamuna and was sent to hell without much hassle.
The Kingdom crippled and a series of murders followed. The heirs designate of Balban, the son of the Martyred Prince Kaikubad, who was declared king at the age of 3 years was killed. There was a war of the races in Delhi, all the Turks, Afghans and Pathans were now to try their sword to decide the fate of India.