Who is called Iron Man of India and why?

Sardar Vallabhbhai Jhaverbhai Patel is known as Iron Man of India. Born in 31 October 1875 in Gujarat, Patel was an Indian lawyer, influential political leader, barrister and statesman who served as the first Deputy Prime Minister and Home Minister of India from 1947 to 1950. After the Indian independence as the first Home Minister and Deputy Prime Minister of India, Patel organized relief efforts for partition refugees fleeing to Punjab and Delhi from Pakistan and worked to restore peace. He led the task of creating a united India, successfully integrating into the newly independent nation those British colonial provinces that formed the Dominion of India. Approximately 565 self-governing princely states had been released from British suzerainty by the Indian Independence Act of 1947 and became part of the Indian Union. Patel persuaded almost every princely state to accede to India. His commitment to national integration in the newly independent country was total and uncompromising, earning him the sobriquet "Iron Man of India"