Princely States were several large and small states in British India ruled by princes with some form of control over their internal affairs as long as they accepted British supremacy. They (565 in number) covered one-third of the land area of the British Indian Empire and one out of four Indians lived under princely rule. Just before Independence, the British gave right to join either India or Pakistan or remain independent to the people of princely states.

Sardar Vallabhbhai Patel, the Home Minister in the interim government, was responsible for unifying these to create a united country I.e. India. He played a crucial role in integrating the princely states in India. It can be seen as following:

• JawaharLal Nehru asked him to integrate the princely states and with the help of VP Menon, Patel drafted an instrument of accession to be signed by the rulers. By signing the instrument, the princely states agreed to hand over control of defence, foreign affairs, and communications to the Union government.
  
  
• Patel also introduced the idea of ‘privy purses,’ making payments to the royal families in lieu of their joining India. Most of the states joined the India, however, some states like Travancore and Bhopal were still hesitant to join India and the Constituent Assembly.
  
  
• Patel took following actions to integrate these princely states:
  
  

• Hyderabad: When the Nizam of Hyderabad was contemplating either remaining independent or joining Pakistan, Patel sent a contingent of troops into the state to support the freedom struggle going on in the state against the Nizam. Within four days, India had control of Hyderabad.
  
  
• Jodhpur: The Prince of Jodhpur wanted to join Pakistan. When Patel got wind of the situation, he immediately contacted him, offering several benefits to get the Prince to accede to India.
  
  
• Junagadh: The Nawab of Junagadh had accepted Pakistan's offer. As the locals revolted against the Nawab, he fled to Karachi. Patel then requested Pakistan to allow organizing a plebiscite in Junagadh. He later sent troops to force the annexation of its three principalities. The Dewan of Junagadh was forced to accede to India. A plebiscite was held, where 91 percent of the population voted to remain in India.
  
  
• Kashmir: The Maharaja of Kashmir, Hari Singh, was reluctant to join either India or Pakistan. When armed tribesmen from Pakistan entered Kashmir, the Maharaja appealed to India for help. Patel and Nehru agreed to send in help if Singh signed the instrument of accession. Thus, Kashmir was included in the Union of India.
  
  
• Manipur: It became a constitutional monarchy in 1948. In the Legislative Assembly of Manipur there were sharp differences over the question of merger of Manipur with India. The Maharaja Bodhchandra was pressured by the government of India to sign the instrument of accession.
  
  

Through his statesmanship, negotiations with princely states through diplomacy and real politic, Sardar Patel managed to bring nearly all of the princely states under the India Union.