The name of the district is derived from its headquarters Sirsa. It is said to be one of the oldest places of North India and its ancient name was Sairishaka, which finds mention in Mahabharata, Panini's Ashatadhayayi and Divyavadan. In Mahabharata, Sairishaka is described as being taken by Nakula in his conquest of the western quarter. It must have been a flourishing city in the 5th century B.C. as it has been mentioned by Panini.