“The king, in his zeal to propagate the faith, now marched against the Hindoos of Nagrakote [Nagarkot Kangra], breaking down their idols and razing their temples. The fort, at that time denominated the Fort of Bheem, was closely invested by the Mahomedans, who had first laid waste the country around it with fire and sword.'…'In the year AH 402 (AD 1011), Mahmood resolved on the conquest of Tahnesur [Thanesar (Haryana)], in the kingdom of Hindoostan. It had reached the ears of the king that Tahnesur was held in the same veneration by idolaters, as Mecca by the faithful; that they had there set up a number of idols, the principal of which they called Jugsom, pretending that it had existed ever since the creation. Mahmood having reached Punjab, required, according to the subsisting treaty with Anundpal, that his army should not be molested on its march through his country…'The Raja's brother, with two thousand horse was also sent to meet the army, and to deliver the following message:- "My brother is the subject and tributary of the King, but he begs permission to acquaint his Majesty, that Tahnesur is the principal place of worship of the inhabitants of the country: that if it is required by the religion of Mahmood to subvert the religion of others, he has already acquitted himself of that duty, in the destruction of the temple of Nagrakote. But if he should be pleased to alter his resolution regarding Tahnesur, Anundpal promises that the amount of the revenues of that country shall be annually paid to Mahmood; that a sum shall also be paid to reimburse him for the expense of his expedition, besides which, on his own part he will present him with fifty elephants, and jewels to a considerable amount." Mahmood replied, "The religion of the faithful inculcates the following tenet: That in proportion as the tenets of the prophet are diffused, and his followers exert themselves in the subversion of idolatry, so shall be their reward in heaven; that, therefore, it behoved him, with the assistance of God, to root out the worship of idols from the face of all India. How then should he spare Tahnesur?"… This answer was communicated to the Raja of Dehly, who, resolving to oppose the invaders, sent messengers throughout Hindoostan to acquaint the other rajas that Mahmood, without provocation, was marching with a vast army to destroy Tahnesur, now under his immediate protection. He observed, that if a barrier was not expeditiously raised against this roaring torrent, the country of Hindoostan would be soon overwhelmed, and that it behoved them to unite their forces at Tahnesur, to avert the impending calamity….”

Tarikh-i-Firishta, translated by John Briggs under the title History of the Rise of the Mahomedan Power in India, first published in 1829, New Delhi Reprint 1981, Vol. I, pp. 27-37.
Quotes from Muslim medieval histories