Thanesar (IAST: Sthāṇvīśvara) is a historic city and Hindu pilgrimage centre in the Kurukshetra district of Haryana, India. It is located approximately 160 km northwest of Delhi. The city Kurukshetra's area merges with Thanesar.
Thanesar was the capital of the Pushyabhuti dynasty, whose rulers conquered most of Aryavarta following the fall of the Gupta Empire. The Pushyabhuti emperor Prabhakarvardhana was a ruler of Thanesar in the early seventh century CE. He was succeeded by his sons, Rajyavardhana and Harsha. Harsha, also known as Harshavardhana, consolidated a vast empire over much of North India by defeating independent kings that fragmented from the Later Guptas.
Harshavardhana (Sanskrit: हर्षवर्धन; 4 June 590 – 647) was an emperor of Kannauj from April 606 until his death in 647. He was the king of Thanesar who had defeated the Alchon Huns, and the younger brother of Rajyavardhana, son of Prabhakaravardhana and last king of Thanesar. He was one of the greatest kings of the Kingdom of Kannauj, which under him expanded into a vast realm in northern India.
At the height of Harsha's power, his realm covered much of northern and northwestern India, with the Narmada River as its southern boundary. He eventually made Kanyakubja (present-day Kannauj, Uttar Pradesh state) his imperial capital, and reigned until 647 CE. Harsha was defeated by the Emperor Pulakeshin II of the Chalukya dynasty in the Battle of Narmada, when he tried to expand his empire into the southern peninsula of India.