Explanation

The Hindu Mahasabha was founded in 1915.

But it gained prominence in 1921.

Madan Mohan Malaviya was one of its key founders and leaders. 

Hindu Mahasabha is a political party in India. 

Founded: 1915

Founders: Vinayak Damodar Savarkar, Pandit Madan Mohan Malaviya, Lala Lajpat Rai