Under whose leadership the Battle of Ten Kings, mentioned in the Rig-Veda, was fought against Sudasa?

The correct answer is Vishwamitra.

In the battle of ten kings, the priest of Bharatas was Vashishta.

• The battle is also called Dasarajna and one of the most important historical events.
• The battle that was fought between Bharatas on one hand and the host of ten chiefs on the other was known as Battle of Ten Kings (Dasraja).
• This battle was fought on the river Parushni, and it gave victory to Sudas, king of Bharatas and established their rule in the upper Gangetic basin where they played an important role in later Vedic times.
• The battle broke out because of a dispute between Vashishta and Vishwamitra.
• Vishwamitra supported the group of ten tribes in which five were Aryans and another five were non-Aryans. 
• The battle was fought between Bharatas on one hand and the group of ten tribes on the other.
• It gave victory to Bharatas and established their supremacy over the region.