Sultan Firuz Tughlaq (1351-88 A.D.) declared that all those who turned Musalman would be exempted from paying Jizya. He says in FutuhÁt-i-Firuz Shahi… - Firuz Shah Tughlaq

I encouraged my infidel subjects to embrace the religion of the prophet, and I proclaimed that every one who repeated the creed and became a Musalman should be exempt from the jizya or poll-tax. Information of this came to the ears of the people at large, and great numbers of Hindus presented themselves, and were admitted to the honour of Islam. Thus they came forward day by day from every quarter, and, adopting the faith, were exonerated from the jizya, and were favoured with presents and honours.

Firoz Tughlaq commanded his ‘fief-holders and officers to capture slaves whenever they were at war”. He had also instructed his Amils and Jagirdars to collect slave boys in place of revenue and tribute.

Some Hindus had erected a new idol-temple in the village of Kohana, and the idolaters used to assemble there and perform their idolatrous rites. These people were seized and brought before me. I ordered that the perverse conduct of the leaders of this wickedness should be publicly proclaimed, and that they should be put to death before the gate of the palace. I also ordered that the infidel books, the idols, and the vessels used in their worship, which had been taken with them, should all be publicly burnt. The others were restrained by threats and punishments, as a warning to all men, that no zimmi could follow such wicked practices in a Musulman country.

Firuz Shah Tughlaq organised an industry out of catching slaves. Shams-i-Siraj Afif writes in his Tarikh-i-Firuz Shahi: “The Sultan commanded his great fief-holders and officers to capture slaves whenever they were at war (that is, suppressing Hindu rebellions), and to pick out and send the best for the service of the court. The chiefs and officers naturally exerted themselves in procuring more and more slaves and a great number of them were thus collected. When they were found to be in excess, the Sultan sent them to important cities… It has been estimated that in the city and in the various fiefs, there were 1,80,000 slaves… The Sultan created a separate department with a number of officers for administering the affairs of these slaves.”. Firuz Shah beat all previous records in his treatment of the Hindus... He records another instance in which Hindus who had built new temples were butchered before the gate of his palace, and their books, images, and vessels of Worship were publicly burnt. According to him “this was a warning to all men that no zimmi could follow such wicked practices in a Musulman country”. Afif reports yet another case in which a Brahmin of Delhi was accused of “publicly performing idol-worship in his house and perverting Mohammedan women leading them to become infidels”. The Brahmin “was tied hand and foot and cast into a burning pile of faggots”. The historian who witnessed this scene himself expresses his satisfaction by saying, “Behold the Sultan’s strict adherence to law and rectitude, how he would not deviate in the least from its decrees.”