Harsha or Harshvardhana (590-647) ruled Northern India for over forty years. He was the son of Prabhakar Vardhan and younger brother of Rajyavardhan, king of Thaneshwar. At the height of his power his kingdom spanned the Punjab, Bengal, Orissa and the entire Indo Gangetic plain.
As a consequence to the coronation of Harshavardhana, dynasty of Thaneshwar and Kannauj amalgamated. Kannauj became a prominent city of North India and for centuries its glory perpetuated, only comparable to Patliputra. It was the desire of every state to rule kannauj. The Chinese traveler, Yhan-Chawang visited the country at the time of Harsha and praised his reign.
After Harsha, there was again political instability in North India. It was difficult to put on record and congruous and consistent history of that period on the basis material available. Only few events, here and there can be reckoned. In the first quarter of the 8th century, Yashoverman established his supremacy over Kannauj. Almost entire India came under his rule and Kannauj regained its lost fame and glory. With the co- operation of Lalitaditya Muktapeed he defended India from Arab’s attack. During that time there was a fear among the neighbouring states due to the Arab’s strength by which they ruled from China, Turkistan to Carboda city of Spain.
Later on, Lalitaditya dethroned and assassinated him in 740 AD. There was a long drawn rivalry among Pals of Bengal, Rashtrakutas of South and Gurjar Pratihars of Gujarat to gain the control of Kannauj. However the ultimate success was achieved by the Gurjar Pratihars. Their empire was vast and famed one, comparable to any king of the Gupta dynasty or emperor Harshavardhan. Gurjar Pratihars dominated the entire 9th and 10th centuries in India. They were defeated by Mohammad Ghaznavi in the year 1018-18.
The Madhyadesh was again in the grip of anarchy with the downfall of Pratihars, but with the emergence of Gaharwar dynasty peace and order was restored and a new era of prosperity began. There were two Gaharwar kings- Govind Chandra and Jaichand. It was the betrayal of Jaichand that Prithviraj was defeated at the hands of Muhammad Ghori at the Tarain in the year 1192. Jaichand himself was later on defeated and killed at Chandwar (Etawah). There was further unrest and invasions continued till the Chandels came to rule. They ruled more than two centuries and brought peace and order.