The long battle for the control over Kannauj was fought among the following dynasties:

Gurjara-Pratihara Dynasty:
- The Gurjara-Pratihara dynasty was a medieval Indian dynasty that ruled over northern India from the 8th to the 11th century.
- They were of Rajput origin and were known for their military prowess and administrative skills.
- The dynasty was founded by Nagabhata I in the 8th century and reached its peak under King Mihira Bhoja.
- The Gurjara-Pratiharas were primarily based in present-day Rajasthan, but they extended their control over a vast territory, including Kannauj.

Rashtrakuta Dynasty:
- The Rashtrakuta dynasty was a royal dynasty that ruled large parts of the Indian subcontinent between the 6th and 10th centuries.
- They originated in the Deccan region and were known for their patronage of arts and literature.
- The Rashtrakutas had a strong military and established an empire that stretched from present-day Gujarat to Andhra Pradesh.
- They clashed with the Gurjara-Pratiharas for control over Kannauj and engaged in several battles with them.

Pala Dynasty:
- The Pala dynasty was a ruling dynasty in Bengal and Bihar from the 8th to the 12th century.
- They were Buddhist rulers and played a significant role in the spread of Buddhism in the region.
- The Palas were known for their administrative efficiency and cultural patronage.
- They too competed with the Gurjara-Pratiharas and Rashtrakutas for control over Kannauj.

Explanation:
- The long battle for control over Kannauj was mainly fought between the Gurjara-Pratihara, Rashtrakuta, and Pala dynasties.
- Kannauj was a strategically important city located on the banks of the Ganges River and was considered the political and cultural center of northern India during that time.
- All three dynasties sought to control Kannauj to establish their dominance over the region and expand their empires.
- The battles for Kannauj were intense and prolonged, involving multiple campaigns and shifting alliances.
- Ultimately, the Gurjara-Pratiharas emerged as the victors and established their authority over Kannauj.
- However, the struggle for control over Kannauj continued for several centuries, with power shifting between different dynasties.
- The battles for Kannauj highlight the political and military rivalries that characterized medieval India and the constant struggle for supremacy among regional powers.