Answer:

Introduction:
The Rashtrakuta dynasty was one of the most powerful and influential dynasties in the history of India. They ruled a large part of the Deccan Plateau from the 6th to the 10th century AD. One of the notable kings of this dynasty was Govinda III, who defeated the Pratihara ruler Nagabhata I.

Background:
The Pratihara dynasty was a prominent dynasty that ruled over northern India from the 6th to the 11th century AD. They were known for their military prowess and had a fierce rivalry with the Rashtrakutas.

Govinda III's Reign:
Govinda III was one of the most powerful kings of the Rashtrakuta dynasty. He ruled from 793 to 814 AD and his reign was marked by several military conquests and territorial expansions. He is known for his successful campaigns against various kingdoms and rulers, including the defeat of Nagabhata I, the Pratihara ruler.

Defeat of Nagabhata I:
Nagabhata I was one of the early rulers of the Pratihara dynasty. He was known for his military feats and had expanded his kingdom in northern India. However, his ambitions clashed with those of Govinda III.

In the early 9th century, Govinda III launched a military campaign against Nagabhata I. The exact details of the battle are not well-documented, but it is believed that Govinda III was able to defeat Nagabhata I and establish his dominance over the Pratihara ruler.

Implications:
The defeat of Nagabhata I by Govinda III had significant implications for the political landscape of northern India. It marked a major setback for the Pratihara dynasty and enhanced the power and influence of the Rashtrakutas.

The defeat also showcased the military prowess of Govinda III and solidified his reputation as a formidable ruler. It further strengthened the Rashtrakuta kingdom and allowed them to expand their territories in northern India.

Conclusion:
In conclusion, Govinda III, one of the powerful kings of the Rashtrakuta dynasty, defeated the Pratihara ruler Nagabhata I. This victory had important implications for the political landscape of northern India and further enhanced the power and influence of the Rashtrakutas.