During the 8th century AD, a struggle for control over the Kannauj took place among three major empires of India namely the Palas, the Pratiharas and the Rastrakutas. The Palas ruled the eastern parts of India while the Pratiharas controlled the western India (Avanti-Jalaor region). The Rastrakutas ruled over the deccan region of India. The struggle for control over Kannuj among these three dynasties is known as the Tripartite struggle in Indian history.
Both Dharmpala, the Pala king and Pratihara king, Vatsaraja clashed against each other for Kannauj. The latter emerged victorious but was defeated by Rashtrakuta King Dhruva I. However, the moment the Rashtrakuta King returned to his kingdom in south, Pala king Dharmapala took the advantage of the situation and captured Kannuj. But his control over Kannauj was temporary.
The tripartite struggle thus started, lasted for two centuries and made all three dynasties weak in the long run. This resulted into the political disintegration of the country and benefited the Islamic invaders from Middle-east.
The significance of Kannauj
Kannauj was located on the Ganga trade route and was connected to the Silk route. It made Kannauj strategically and commercially very important. It was also the erstwhile capital of Harshvardhana's empire in north India.