An important ruling family to gain prominence after the fall of the Gupta was that of the Pushyabhutis who had their capital at Thanesar (Thanesvara in Kurukshetra). The dynasty became influential with the accession of Prabhakarvardhana, who was able to defeat the Hunas and strengthen his position in the regions of Punjab and Haryana.
After his death, his elder son Rajyavardhana came to the throne but he was treacherously killed by Shashanka, the king of Bengal and Bihar. Harshavardhana then ascended the throne in AD 606. He was only sixteen years of age at that time. Still he proved himself to be a great warrior and an able administrator.
We have two valuable sources that throw important light on the life and times of Harshavardhana (606 - 647). These are Harshacarita written by his court poet Banabhatta and Si-Yu-Ki, the travel account of the Chinese Buddhist pilgrim Hsuan Tsang, who visited India during AD 629 - 644.
After his accession Harshavardhana united his kingdom with that of his widowed sister Rajayashri and shifted his capital to Kanauj and is described as the lord of the north (sakalauttarapathanatha). He brought Punjab, Uttara Pradesh, Bengal, Bihar and Orissa under his control. Harsha wanted to extend his power in the Deccan. But he was defeated by Pulakesin II, the Chalukya ruler, on the banks of river Narmada. The river thus became the southern boundary of his kingdom.
The death of Harsha in AD 647 was followed by a political confusion that continued up to the eighth century when the Gurjara Pratiharas, the Rajput rulers, emerged as a big force in northern India.