Sorry, this page is not yet written: the following is a outline of the political situation.
The line of Nagabhata, 8-11 century AD, was first centered at Ujjain and then at Kanauj. Nagabhata's relation to the line of Harichandra of Marwar is unclear. Nagabhata I might have ruled in Marwar, his grandnephew Vatsaraja (around 783) ruled in Ujjain and was defeated by the Rashtrakuta Dhruva (780-3), and his son Nagabhata II, in turn, probably captured Kannauj in 816 from Chakrayudha, who was put on throne by Dharmapala (The Palas of Bengal had arisen under Gopala, reigned 750-770, and Dharmapala, reigned 770-810, and then under Devapala, reigned 810-850). He however lost it to Rashtrakuta Govinda III (793-814), and his son Ramabhadra (reigned 833-836) was weak. Then his son MihiraBhoja I (reigned 836-890) probably regained Kanauj and his son Mahendrapala (reigned 890-910) made it a great empire conquering part of the Pala territory. After this things are a bit unclear: Rashtrakuta Indra III sacked Kanauj in 916 by defeating probably Mahipala (908-942) (his relation to the earlier pratiharas is unclear), and Pratihara power declined. Rajyapala, their last important king was ousted from Kanauj by Mahmud (son of Sebuktigin, turkish governor of ghazni, died in 1030) of Ghazni in 1018, and was killed by Chandela Vidyadhara. The pratiharas probably survived for another generation till 1027.
The Gurjaras were Hindu kings: the theory that they descended from the White, or eastern, Huns is probably unfounded. The Palas in Bengal on the other hand were Buddhists (and sent many missionaries to Tibet) centered around Mudgagiri (Monghyr) of current day Bihar, and regained power under Mahipala I (reigned 988-1038), only to decline again. The last important Pala king Ramapala reigned 1077-1120 A.D., though they survived for about 40 years longer in Southern Bihar. In Kanauj, after the fall of the Pratiharas power passed on to the Gahadavala dynasty (late 11th to mid 13th century, though at Kannauj only till 1197 A.D. when he was displaced by Qutb-ud-din Aibak, a slave general of Sultan Muhammad of Ghur) and like most North Indian states at that time, was marked by an extremely strong feudal structure based on the Brahminical religious tradition. Vijayachandra (reigned 1155-69 A.D.) was an important king of this dynasty.