Hisar city, previously spelled as Hissar, is the administrative headquarters of Hisar district in the state of Haryana, in northwestern India. It is situated 164 kilometre northwest of Delhi on the National Highway NH10.

According to V.S. Agarwala, Aisukari or Isukara, a beautiful and prosperous city of Kuru Janapada referred to by Paniniin Ashtadhyavi, was the ancient name of Hisar. However, the antiquity of the area can be established on the basis of the discovery of pre-historic and historical sites at a number of places in the district3. some of the most prominent sites are Banawali, Rakhigarhi, Seeswal, Agroha and Hansi. The earliest settlers in the district were pre-Harappans who, in the first half of the 3rd millennium B.C. are supposed to have migrated to Banawali from north Rajasthan.

Marauding Muslim invaders and rulers of Delhi destroyed these Hindu and Jain temples. After destroying these temples, Firoz Shah Tughlaq, used the rubble from these temples and built a fort at Iksaru and renamed the town after himself as 'Hissar-e-Firoza' meaning 'Fort of Firoz'. Evidence of these destroyed temples can be still be seen in the material used in the Islamic fort at Hissar as some of the material has beautiful Hindu and Jain motifs, carvings, etc.