
Vatsaraja

Vatsaraja (780–800) or Vatsraja was one of the rulers of Gurjara-Pratihara dynasty. He was grand-nephew of Nagabhata I and his mother was queen Bhuyikadevi. He was the first ruler of Rajasthan to win victories over the distant regions of Kanauj and Bengal. His extensive conquests mark the rise of the Imperial Pratiharas.
Reign.
After Nagabhata I, he was succeeded by his nephews, there have been two rulers namely Kakkuka and Devaraja before Vatsraja came to the throne. Kakustha or Kakkuka was the nephew of Nagabhata I and nothing much is known about him. The younger brother of Kakkuka, king Devasakti or Devaraja is described as having curbed the freedom of a multitude of rulers.
After broughting much of Rajasthan under his control, Vatsaraja then embarked to become "master of all the land lying between the two seas." Contemporary Jijasena's Harivamsha purana describes him as "master of western quarter" 
According to Radhanpur Plate Inscription and Prithviraja Vijaya ,Vatsaraja led an expedition against the distant eastern kingdom of Bengal, ruled by the Palas under Dharmapala. as such palas came into conflict from time to time with the Imperial Pratiharas.
According to above inscription Dharamapala, was deprived of his two white Royal Umbrellas, andfled, pursued by the Pratihara forces under Vatsaraja's General Durlabhraj Chauhan of Shakambhari. The Prithviraja Vijaya describes Durlabhraj Chauhan as having “washed his sword at the confluence of the river Ganga and the ocean, and savouring the land of the Gaudas”, The Baroda Inscription ( AD 812) also refers to Nagabhata's victory over the Gauda king Dharmapala.
Through vigorous campaigning, Vatsraja had extended his dominions to include a large part of northern India, from the Thar Desert in the west up to the frontiers of bengal in the east. 
The statement of Jaina preceptor Uddyotana Suri, that the narrative "Kuvalayamala" was composed by him at Jalor in AD 778 when the ruling king was Vatsaraja, reveals that Vatsaraja ruled at Rajputana. The evidence of the 795 CE inscription of his subordinate, brought to light by Shanta Rani Sharma, presents a detailed record of his victories over the Arabs, Indrāyudha and Bengal. It also presents evidence that contests the claim of the defeat of Vatsaraja by Dhruva. According to the Gwalior inscription of his later descendant Bhoja, Vatsaraja had ‘subdued the entire world’, and was the ‘foremost among the most distinguished Kshatriyas’. It also mentions the defeat of the famous Bhandi clan by Vatsaraja. Palas were subordinate to Vatsaraja.