Parts of Rajasthan may have been occupied by the Indus Valley Civilization (Harappans). Excavations at Kalibanga in northern Rajasthan around 1998 revealed the existence of human settlements of Harappan times on the banks of a river that dried up later, which some people believe to be the Saraswati.
Rajasthan’s geographic position in India has caused it to be affected by the expansionist efforts of various empires.It was a part of the Mauryan Empire around 321-184 BCE. It had also been a part of Republics like Arjunyas, Hunas, Kushans, Malavas, Saka Satraps and the Yaudheyas. The Guptas reigned in the 4th century. Some Buddhist caves and Stupas have been found in Jhalawar, in the southern part of Rajasthan. The decline of the 300 year old Gupta Empire in the 6th century led to the political unrest in the Northern India and was followed by an epoch of instability as numerous chieftains tried to gain power. The situation was stabilized when the Gurjara-Pratiharas, the earliest of the Gurjar clan emerged around 700 CE. Gurjar pratihars were well known for their hostility towards Arab invaders.The Arab chronicler Sulaiman describes the army of the Gurjar Pratihars as it stood in 851 CE, The king of Gurjars maintains numerous forces and no other Indian prince has so fine a cavalry. He is unfriendly to the Arabs, still he acknowledges that the king of the Arabs is the greatest of kings. Among the princes of India there is no greater foe of the Islamic faith than he. He has got riches and his camels and horses are numerous.