Wikipedia
Mewat is also a historical region of Haryana and Rajasthan states in northwestern India. The loose boundaries of Mewat are not precisely determined but generally include Mewat District of Haryana and parts of Alwar, Bharatpur, and Dholpur districts of Rajasthan.
The region roughly corresponds to the ancient kingdom of Matsya, founded in the 5th century BCE. Mewati dialect, a slight variant of the Haryanvi and Rajasthani dialects, of Hindi is spoken in rural areas of the region. Mewati Gharana is well known Gharana of Indian classical music.
Mewat District is a district of Haryana state in India. It is located at southern edge of Haryana. Its area is 1,912 square km and the population is one million. It is semi-arid and its economy is mainly rain-fed agriculture. Nuh is the district headquarter of Mewat.
Hasan Khan Mewati is most well know chieftian of Mewat. He fought against Babur in Battle of Khanwa in 1527. Under Mughal rule Mewat came under Rajputs. It was a part of Alwar princely state until independence. The Delhi-Gurgaon-Alwar-Jaipur highway used to pass through Mewat until late 1960s when the new national highway (NH 8) was constructed bypassing Mewat.