Why is Shivaji Maharaja entitled with the word Chatrapati before his name?

Over the course of his life, Shivaji engaged in both alliances and hostilities with the Mughal Empire, the Sultanate of Golkonda and the Sultanate of Bijapur, as well as with European colonial powers. Shivaji's military forces expanded the Maratha sphere of influence, capturing and building forts, and forming a Maratha navy. Shivaji established a competent and progressive civil rule with well-structured administrative organisations. He revived ancient Hindu political traditions and court conventions and promoted the usage of the Marathi language.

Shivaji's legacy was to vary by observer and time, but nearly two centuries after his death, he began to take on increased importance with the emergence of the Indian independence movement, as many Indian nationalists elevated him as a proto-nationalist and hero of the Hindus.