Keshav Sitaram Thackeray, commonly known by his pen name Prabodhankar Thackeray, was an Indian politician, social activist and author. He was one of the key leaders of the Samyukta Maharashtra Samiti which successfully campaigned for the linguistic state of Maharashtra. He was the father of Bal Thackeray, who founded Shiv Sena, a Marathi Hindu regionalist party. He is also the grandfather of Shiv Sena leader Uddhav Thackeray and Maharashtra Navnirman Sena chief Raj Thackeray.