Nagaur or Naga-Pur is referred to in the Mahabharata. The kingdom of Ahichhatrapur which Arjuna is said to have conquered and subsequently offered to his Guru Dronacharya, was perhaps some of the areas of the Nagaur district. It was the capital of Jangladesh. The foundation of city dates back to 4th century BC. Nagas originally ruled over this place and about 7th century onwards the Chauhans became the overlords of Nagaur and it was included in Sapadalaksha. The city was at the center of Muslim invasion from Central Asia. The fort is of historical importance. The Rajput rulers dominated Nagaur for a longer period. Nagaur ruler was repeatedly forced to pay tribute to the Sesodias of Chittor while their lands were slowly annexed by the Rathors of Jodhpur. In fact, the case of Nagaur vividly illustrates the turning back of the tide of Islamic conquests in Rajputana in the 14th and 15th Centuries. Nagaur, north to Bikaner, and up to the border of Punjab, was called Jangladesh in ancient times. The remains of some of the earliest settlements along the banks of the long dried-up Saraswati River can be seen to this day—in a later age, it came under the Naga rulers after whom the town of Nagaur (Naga-pura) is named.