The United States of Matsya also called Matsya Union was a State

State

A state is an organized political community, living under a government. States may be sovereign and may enjoy a monopoly on the legal initiation of force and are not dependent on, or subject to any other power or state. Many states are federated states which participate in a federal union...

 of India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 which was formed on March 17, 1948 by the merger of four erstwhile princely state

Princely state

A Princely State was a nominally sovereign entitity of British rule in India that was not directly governed by the British, but rather by an Indian ruler under a form of indirect rule such as suzerainty or paramountcy.-British relationship with the Princely States:India under the British Raj ...

s, Alwar, Bharatpur

Bharatpur, India

Bharatpur is a city in the Indian state of Rajasthan. It was founded by Maharaja Suraj Mal in 1733. Located in the Brij region, Bharatpur was once an impregnable, well-planned and well-fortified city, and the capital of Jat kingdom ruled by Sinsinwar Maharajas.The trio of Bharatpur, Deeg and...

, Dholpur

Dholpur

Dholpur is a city in eastern-most parts of the Rajasthan state of India. It is the administrative headquarters of Dholpur District and was formerly seat of the Dholpur princely state, before Independence....

, and Karauli

Karauli

Karauli is a town lying in the Indian state of Rajasthan. The town is the administrative center of Karauli District, and was formerly the capital of the erstwhile princely state of Karauli.-Geography:...

 after accession. Shobha Ram was the first and last chief minister of the State from 18 Mar 1948 till 15 May 1949. On May 15, 1949, the Matsya Union was merged with Greater Rajasthan, to form the United State of Greater Rajasthan, which later became the state of Rajasthan

Rajasthan

Rājasthān the land of Rajasthanis, , is the largest state of the Republic of India by area. It is located in the northwest of India. It encompasses most of the area of the large, inhospitable Great Indian Desert , which has an edge paralleling the Sutlej-Indus river valley along its border with...

on January 26, 1950.