Chandragupta Maurya defeated the last Nanda king, Bhadrasala.

Background:
The Nanda dynasty was a powerful ruling dynasty in ancient India that existed from 364 BC to 322 BC. The last Nanda king was Bhadrasala, who ruled over a vast empire. However, his reign was marked by dissatisfaction among his subjects and the rise of several regional powers that challenged Nanda authority.

Chandragupta Maurya:
Chandragupta Maurya was a young prince who hailed from the Magadha region, which was under Nanda control. He was a gifted military strategist and had a burning desire to overthrow the Nandas and establish his own empire. Chandragupta sought the guidance of Chanakya, a renowned scholar and political strategist, who became his mentor.

Alliance with other regional powers:
Chandragupta realized that he couldn't defeat the mighty Nandas alone. Therefore, he formed alliances with other regional powers who were also unhappy with Nanda rule. One of his key allies was Parvataka, the ruler of a kingdom in western India.

The Battle:
Chandragupta and his allies launched a coordinated attack on the Nanda empire. They strategically targeted the weak points of the Nanda army and utilized guerrilla warfare tactics to gain the upper hand. The battle was fierce, but ultimately Chandragupta's forces emerged victorious.

Consequences:
With the defeat of Bhadrasala and the fall of the Nanda dynasty, Chandragupta Maurya established the Maurya Empire, which would go on to become one of the largest and most powerful empires in ancient India. Under Chandragupta's rule, the Maurya Empire expanded and flourished, encompassing a vast territory.

Conclusion:
In conclusion, Chandragupta Maurya defeated the last Nanda king, Bhadrasala, through strategic alliances, military prowess, and the guidance of his mentor, Chanakya. This victory marked the end of the Nanda dynasty and the rise of the Maurya Empire.