In short, when Muhammad Bakhtiyar became aware of the nature of the country, and saw that his men were tired and exhausted, and that many had been sl… - Muhammad bin Bakhtiyar Khalji

One night in the year 641 (1243A.D.) he halted at a place between Deo-kot and Bangawan, and stayed as a guest in the house of Muatamadu-d daula, who had formerly been an equerry in the service of Muhammad Bakhtiyar and had lived in the town of Lakhnauti. From this man he heard that after passing over the bridge, the road lay for fifteen stages through the defiles and passes of the mountains, and at the sixteenth stage level land was reached. The whole of that land was well populated, and the villages were flourishing. The village which was first reached had a fort, and when the Muhammadan army made an attack upon it, the people in the fort and the surrounding places came to oppose them, and a battle ensued. The fight raged from morning till the time of afternoon prayer, and large numbers of the Muhammadans were slain and wounded. The only weapons of the enemy were bamboo spears; and their armour, shields and helmets, consisted only of raw silk strongly fastened and sewed together. They all carried long bows and arrows. When night came on, the prisoners who had been taken were brought forward and questioned, and it was then ascertained that at five parasangs from that place there was a city called Karam-batan, and in it there was about three hundred and fifty thousand brave Turks armed with bows. The moment the horsemen of the Muhammadans arrived, messengers went to report their approach, and these messengers would reach their destination next morning. When the author was at Lakhnauti, he made enquiries about that place, and learnt that it was a pretty large city. The ramparts of it are built of stone. The inhabitants of it are Brahmans and Nunis, and the city is under the sway of the chief of these people. They profess the Buddhist religion. Every morning in the market of that city, about fifteen hundred horses are sold. All the saddle horses which come into the territory of Lakhnauti are brought from that country. Their roads pass through the ravines of the mountains, as is quite common in that part of the country. Between Kamrup and Tibet there are thirty-five mountain passes through which horses are brought to Lakhnauti.

The Mussalman invaders sacked the Buddhist universities of Nalanda, Vikramshila, Jagaddala, Odantapuri to name only a few. They razed to the ground Buddhist monasteries with which the country was studded. The monks fled away in thousands to Nepal, Tibet and other places outside India. A very large number were killed outright by the Muslim commanders. How the Buddhist priesthood perished by the sword of the Muslim invaders has been recorded by the Muslim historians themselves. Summarizing the evidence relating to the slaughter of the Buddhist Monks perpetrated by the Musalman General in the course of his invasion of Bihar in 1197 AD, Mr. Vincent Smith says, "The Musalman General, who had already made his name a terror by repeated plundering expeditions in Bihar, seized the capital by a daring stroke... Great quantities of plunder were obtained, and the slaughter of the 'shaven headed Brahmans', that is to say the Buddhist monks, was so thoroughly completed, that when the victor sought for someone capable of explaining the contents of the books in the libraries of the monasteries, not a living man could be found who was able to read them. 'It was discovered,' we are told, 'that the whole of that fortress and city was a college, and in the Hindi tongue they call a college Bihar.' "Such was the slaughter of the Buddhist priesthood perpetrated by the Islamic invaders. The axe was struck at the very root. For by killing the Buddhist priesthood, Islam killed Buddhism. This was the greatest disaster that befell the religion of the Buddha in India....

It is related that this Muhammad Bakhtiyar was a Khilji, of Ghor, of the province of Garmsir. He was a very smart, enterprising, bold, courageous, wise, and experienced man… Being a bold and enterprising man, he used to make incursions into the districts of Munir (Monghir), and Behar, and bring away much plunder, until in this manner he obtained plenty of horses, arms, and men. The fame of his bravery and of his plundering raids spread abroad, and a body of Khiljis joined him from Hindustan. His exploits were reported to Sultan Kutbu-d din, and he sent him a dress and showed him great honour. Being thus encouraged, he led his army to Behar and ravaged it. In this manner he continued for a year or two to plunder the neighbourhood, and at last prepared to invade the country.