Modern Rajasthan includes most of Rajputana, which comprises the erstwhile nineteen princely states, two chiefships, and the British district of Ajmer-Merwara. Marwar (Jodhpur), Bikaner, Mewar (Chittorgarh), Alwar and Dhundhar (Jaipur) were some of the main Rajput princely states. Bharatpur and Dholpur were Jat princely states whereas Tonk was a princely state under a Muslim Nawab. Rajput families rose to prominence in the 6th century CE. The Rajputs put up a valiant resistance to the Islamic invasions and protected this land with their warfare and chivalry for more than 500 years. They also resisted Mughal incursions into India and thus contributed to their slower-than-anticipated access to the Indian subcontinent. Later, the Mughals, through skilled warfare, were able to get a firm grip on northern India, including Rajasthan. Mewar led other kingdoms in its resistance to outside rule. Most notably, Rana Sanga fought the Battle of Khanua against Babur, the founder of the Mughal empire.

How many princely states of Rajputana contain?