The Police Action, also known as Operation Polo, was a military operation undertaken by the Indian government in September 1948 to integrate the princely state of Hyderabad into the newly formed Indian Union. The operation marked the end of the rule of the Nizam of Hyderabad and the annexation of the state into the Indian Union.

Here are the key events leading to the Police Action and the end of Nizam rule:

1. Hyderabad State:

o Hyderabad was one of the largest and wealthiest princely states in British India. It was ruled by Mir Osman Ali Khan, the seventh and last Nizam. The Nizam opted for independence at the time of India's partition in 1947.

2. Integration Dilemma:

o The Nizam's decision to remain independent led to a complex situation. Hyderabad was surrounded by Indian territories, and its geographical location in the heart of the Indian subcontinent made its independence challenging. The Indian government, led by Sardar Patel, was determined to integrate all princely states into the Indian Union.

3. Razakar Movement:

o The Razakars, a private militia loyal to the Nizam, engaged in violence and suppression against those advocating for integration with India. The Razakar movement exacerbated communal tensions and atrocities against non-Muslims.

4. Indian Government's Ultimatum:

o The Indian government called upon the Nizam to accede to India or face military action. The Nizam, reluctant to integrate, sought assistance from the United Nations and appealed for international intervention.

5. Operation Polo (Police Action):

o  On September 13, 1948, the Indian government, under Home Minister Sardar Vallabhbhai Patel, ordered the military invasion of Hyderabad, citing the law and order situation as justification. The Indian military, under the command of Major General J.N. Chaudhuri, launched Operation Polo. The military action was swift and successful, and Indian forces rapidly advanced into Hyderabad.

6. End of Nizam Rule:

o The military operation resulted in the defeat of the Nizam's forces and the surrender of the Hyderabad state. On September 17, 1948, the Nizam formally signed the Instrument of Accession, integrating Hyderabad into the Indian Union. The end of Nizam rule marked the completion of the annexation process.

7. Aftermath:

o The integration of Hyderabad into India brought an end to the princely state's independence and its unique status. The annexation had significant consequences for the political and social dynamics of the region, including the incorporation of Telangana into the Indian state.

8. Telangana Region:

o The integration of Hyderabad led to the reorganization of states in India. The Telangana region, which was part of the former Hyderabad state, went through various administrative changes over the years and eventually became a separate state, Telangana, in 2014.

The Police Action and the annexation of Hyderabad were significant events in the process of integrating princely states into the Indian Union after independence. The operation aimed to bring an end to the independent rule of princely states and ensure their inclusion in the newly formed democratic republic of India.