The State of Hyderabad in the Deccan officially acceded to the Indian Union in the year

The State of Hyderabad officially acceded to the Indian Union in 1948 following a military intervention known as 'Operation Polo' or 'Police Action' [1]. Initially, the Nizam of Hyderabad sought independent status and signed a Standstill Agreement with India in November 1947 [2]. However, internal instability caused by the oppressive rule of the Nizam's militia (the Razakars) and the Telangana peasantry movement led to significant violence [3]. In response, the Indian government launched a military operation on September 13, 1948 [2]. The Hyderabad forces, led by Major General El Edroos, surrendered within five days on September 17–18, 1948 [2]. Following this defeat, the Nizam signed the Instrument of Accession, formally integrating the state into the Indian Union in 1948. While a formal constitutional ceremony occurred later in 1950, the official accession and annexation were finalized in 1948 [1].

Sources

1. [1] Rajiv Ahir. A Brief History of Modern India (2019 ed.). SPECTRUM. > Chapter 34: The Indian States > Plebiscite and Army Action > p. 608
2. [2] Politics in India since Independence, Textbook in political science for Class XII (NCERT 2025 ed.) > Chapter 1: Challenges of Nation Building > Hyderabad > p. 17
3. [3] History , class XII (Tamilnadu state board 2024 ed.) > Chapter 8: Reconstruction of Post-colonial India > 8.3 Merger of Princely States > p. 106