As the guptas weakened by the combined attack of the hUNas in the 5th cent AD and yashodharmman from the mAndAsor region, their representatives often declared their independence, as was done by shaiva hindu vainyagupta (or nainyagupta 501–9 AD) in samataTa (he may later have become a gupta emperor). In fact it is possible that some part of Bengal was under the overlordship of yashodharmman only for a short while. bardhamAna under vijaYasena (he and and maharaja rudradeva at the same time seem more like feudatories already in this late gupta period rather than provincial governors) was under the overlordhip of vainyagupta, but became independent soon after. In the sixth century, for some 35 years, vaGga was ruled by gopacandra (son of dhanacandra and giridevI who are not referred to as kings; he was overlord of vijaYasena, probably the same as the abovementioned one), dharmAditya and narendrAditya samAcAradeva (possibly ruling all the way to nAlanda); and for a short period was also ruled by the cAlukya king kIrtivarmA. Other kings whose names are known from coins of this period include pRthuvIra and shrIsudhanyAditya, but almost nothing is known about them.
North and west bengal was disputed territory in the war between the later guptas and the maukharIs from the current Uttar Pradesh region. IshAnavarmA of the maukhari's claims to have defeated the gauD.as, and kumAragupta and his son dAmodaragupta claim to have defeated the maukharis. Similarly, IshAnavarmA's successors, sharvavarmA (550–4 AD) and avantivarmA (569–70 AD), claim to have regained parts of magadha, but mahAsenagupta (till about 595 AD) seems to have been a powerful ruler who ruled all the way east to the brahmaputra;in fact he fought and defeated susthitavarmmaNa of kAmarUpa and took his sons prisoners.
gauD.a was a powerul force in the already in the middle of the sixth century AD and, before 606 AD, declared its independence from either mahAsenagupta (brother of wife of puSyabhuti king prabhAkaravardhhana of thAneshvara, father of rAjyavarddhana, harSavarddhana and devashrI, wife of grahavarmA) or devagupta (ruler of mAlava, later allied to shashAGka against maukharI king grahavarmA, son of avantivarmA) towards the end of the century under anti-buddhist shaiva hindu shashAGka and controlled all of Bengal except possibly samataTa, and beyond as well; though the empire fell apart soon after under his son mAnava, who may have ruled for only 8 months and 5 days. Nothing much is known about shashAGka's origins: there is no evidence for the claims that he was narendragupta of the later guptas; it is likely that he was a provincial governor (mahAsAmanta) under the guptas. He defeated and killed buddist rAjyavarddhana, who had allied with shaiva hindu king bhAskaravarmA of kAmarUpa, and possibly fought a indecisive war with harshavarddhana as well. He was definitely a powerful king in 619 AD (with his own feudatories; the shailodbhava kings of koGgoda in orissa are under his dominion), and might have ruled till about 637 AD.
In 638 AD, chinese traveler Hieuentsang describes five regions in bengal: kajaGgala (near rAjamahala), puNDravarddhana (north bengal), karNasuvarNa (west bengal), samataTa (east bengal) and tAmralipta (medinipura); but he gives no indication that these were independent kingdoms. bhAskaravarmA conquered puNDravarddhana and karNasuvarNa by 648 AD and harshavarddhana conquered magadha from purNavarmA by 641 AD and koGgoda and kajaGgala by 642 AD, but he died in 646–7 AD, around which time we find a jaYanAga in karNasuvrNa, but nothing much is known about him. After that, buddhist tibetan kings srang-tsana-gampo (600–650 AD) and ki-li-pa-pu (650–679 AD) defeated magadha and kAmarUpa and became rulers of much of north India, though magadha proper, remained under Adityasena gupta, great grandson of mahAsenagupta and his three descendants till the first quarter of the eighth century. A revolt in 702 AD in north India was unable to throw the tibetans out. Their influence lasted a long time. Even in the late eighth century, khree-srang-lde-vtsan (755–797 AD) and his son mu-tig-vtsan-po are claiming they are overlords of dharmapAla and nArayaNapAla, and in the ninth century ral-pa-chan (c 817–836) claims to have conquered Bengal. These encounters destabilized an already unstable situation.
In the mid seventh century, immediately following shashAGka, samataTa may have been ruled by a bhadra dynasty: Hieuentsang mentions shIlabhadra as king of samataTa, bhAskaravarmA mentions a governor jyeSThabhadra, and jaYanAga mentions a governor nArAYaNa bhadra, though in vIrabhUma murshidAbAda region. For the first three-quarters of the seventh century, one finds the bauddha kings khaD.godyama, jAtakhaD.ga, devakhaD.ga (who might be the same as a devavarmA) and rAjarAja bhaTTa (who might be the same as a rAjabhaTa) in vaGga and samataTa with capital possibly at karmAnta; but they may not have been totally independent. Nothing is known about the origin of the khaD.gas, but they may be related to the nepalese kharka whose king dravyasAha in the 16th century founded the gurkhA kingdom.
In the middle half of the 7th century we also find the hindu dynasty of pratApopanatasAmantacakra-shrIjIvadharaNa rAta, samataTeshvara prAptapancamahAshabda shrIshrIdhAraNa rAta, and baladhAraNa rAta ruling in samataTa with capital at devaparvata surrounded by kSIroda river, and again probably not independent. A deva dynasty (buddhist kings shAntideva, vIradeva, Anandadeva and bhavadeva, all called paramasaugata paramabhaTTAraka parameshvara rAjAdhirAja) is also found ruling from devaparvata in paTikera in samataTa; but it is not clear whether they are from this period or slightly later. One also knows of adhimahArAja, mahAsAmanta shivanAtha, shrInAtha, bhavanAtha and lokanAtha (around 663 AD or 750 AD) ruling in tripurA or samataTa probably under the overlordship of khaD.gas or the rAtas. Mention is also found of the governor shrImaruNDanAtha bhaTTAraka from shrIhaTTa, and he seems to be related to lokanAtha.
But in the second quarter of the eighth century, the shaila dynasty (probably from the mountains, or related to the shailodbhava dynasty mentioned above) killed the ruler and occupied puNDra according to jaYavarddhana II who claims to be the greatgradson of the brother of this king of shaila dynasty. In 725–735 AD, yashovarmA conquered first magadha and gauD.a (which may have been the same) and then vaGga. Sometime soon after, kashmir king lalitAditya defeated yashovarmA, invited the king of gauD.a and killed him. During his grandson jayApID.a's time, rAjataraGginI (describing 8th century bengal) mentions gauD.a being one of the five semi-independent regions of bengal under jaYanta, who won over them all. In 748/759 AD vagadatta king harSa, possibly king of kAmarUpa and father in law of jayadeva, king of licchavis (alternatively, of kara dynasty of Orissa who also claim to be descendants of the bhagadatta dynasty) conquered gauD.a, oDra, kaliGga and koshala. After the khaD.gas, vaGga may have been under the candras till the first quarter of the eighth century: There is a buddhist tibetan tradition naming vRkSacandra, vigamacandra, kAmacandra, siMhacandra etc., ening with vimalacandra, his son govicandra, and relative lalitacandra. lalitacandra was probably defeated by yashovarmA. The kingdoms of Bengal were very fragmented during this hundred year.
There were of course a lot of local dynasties which lasted a long time. Thus, around 7th century, raghunAtha Adimalla founded the malla dynasty ruling parts of West Bengal (around viSNupura) for a thousand years. Important kings in this dynasty are jagat malla (ruler in 994 AD) and virhAmbIra (ruling in 1587). The early rulers were shaivaites, the later ones vaishnavaites. Similarly, one finds record of a dynasty founded by a Dhimantasena, son of Bhimasena, who defeated the kirATas of bhabalina (current savar in Bangladesh). His son Ranadhirsenas's son Harish Chandra Pal's son Mahendra dedicated a matha in Saka 791 (869 AD). (The coins from Savar from the post-gupta period name shrikrama and sudhanya.)
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