Dissolving
In 1956 during the Reorganisation of the Indian States based along linguistic lines, the state of Hyderabad was split up among Andhra Pradesh, Bombay state (later divided into states of Maharashtra and Gujarat in 1960 with the original portions of Hyderabad becoming part of the state of Maharashtra) and Karnataka.
In December 1953, the States Reorganization Commission was appointed to prepare for the creation of states on linguistic lines. The commission, due to public demand, recommended disintegration of Hyderabad state and to merge Marathi speaking region, Maratwada, with Bombay state and Kannada speaking region with Mysore state. The States Reorganisation Commission (SRC) was not in favour of an immediate merger of Telugu speaking Telangana region of Hyderabad state with Andhra state, despite their common language. Para 378 of the SRC report said "One of the principal causes of opposition of Vishalandhra also seems to be the apprehension felt by the educationally backward people of Telangana that they may be swamped and exploited by the more advanced people of the coastal areas."
Andhra state and Telangana were merged to form Andhra Pradesh state on 1 November 1956 after providing safeguards to Telangana in the form of Gentlemen's agreement. There is ongoing movement in Telangana region to invalidate the merger.
Read more about this topic: Hyderabad State