Ahmad Shah Abdali, the ruler of Afganistan regarded the Indian regions occupied by Nadir Shah in the east to be under his dominion. Various Rohila and Afghan Pathans were also inspiring Abdali to invade upon India. On the other hand, Maratha power had expanded in Northern India.

In the end of 1759, Abdali ousted the Maratha representative from Punjab and reached near Delhi. The Peshwa sent a massive army under the leadership of his cousin Sadashivrao Bahu and his son Vishwas Rao against Abdali which occupied Delhi and reached the battlefield of Panipat where on 14th January 1761, the third Battle of Panipat was fought and Marathas were defeated in the end.

Causes of Marathas’ Defeat in the war:

1. The defective military organization and lack of discipline in Marathas. 

2. Lack of unity between the Indian kings and chieftains. 

3. The Marathas were deprived of assistance from Jats, Rajputs and other Indian powers as they lacked in unity. 

4. Several traitors supported Abdali, so the Marathas were forced to fight alone.