The primary series of Western Chalukyan invasions, which was to devastate Vengi during the next century and a quarter, transpired during the early years of rule Saktivarman I (c. 1000 -1011 C.E.). Satyasraya (997 - 1008 C.E.), the son and successor of Tailapa II, sent an army led by one of his generals Baya Nambi to invade the Eastern Chalukyan kingdom in 1006 C.E. to overthrow the Chola-Chalukya alliance and bring the east coast under his control. The general entered Vengi from the south condensed the forts of Dharanikota and Yanamadala to ruins and established himself at Chebrolu (Guntur district).
Rajaraja Chola diverted the concentration of Satyasraya by conveying his son Rajendra Chola I to plague Rattapadi in the west and thereby obligated him to extract his army from Vengi for the defense of his dominion. Following the retreat of the Western Chalukyan army from the east coast, Saktivarman overtook the control of his kingdom.
Succession Disputes
Toward the conclusion of the sovereignty of Vimaladitya (1011 - 1018 C.E.) the succession to the Vengi throne was in dispute. His son Rajaraja Narendra, through the Chola princess Kundavai, was allotted crown prince and ascended his father on the throne of Vengi. But Vijayaditya VII, who was the stepbrother of Rajaraja Narendra, detained power with the help of Jayasimha II, the Western Chalukyan ruler. Rajaraja Narendra sought the aid of his maternal uncle and overlord, the Chola emperor Rajendra Chola I. The latter swiftly transmitted forces to his serve. Rajendra sustained the ritual of fighting on two fronts in the north, started by Rajaraja Chola, as well. Rajendra Chola I sent a powerful army against Rattapadi to divert the attention of Jayasimha II and prevent him from sending effective help to Vijayaditya VII. With this, the king of Kalyani was compelled to take steps for the defence of his kingdom.
On the Eastern Chalukyan front, the Chola army led by the general Soliyavarasan overpowered Vijayaditya and his Kalinga and Odda supporters in numerous skirmishes, took control of the nation on behalf of Rajaraja Narendra and advanced afterwards on a grand military expedition to the Gangetic valley. To protect the rear of his army campaigning in the Gangetic valley, Rajendra Chola I rested on the banks of the Godavari, during which he instated his nephew Rajaraja Narendra as the ruler of Vengi and celebrated the latter`s coronation on 16th August 1022 A.D. later he conferred his daughter Ammangai in marriage to his nephew whose son Rajendra was named after him.
Rajaraja Narendra was persistently inundated with difficulties during his elongated rule of 41 years. His half-brother Vijayaditya never gave up his designs upon the throne. He managed to oust his brother, seize the throne and keep himself in power, probably with the help from the Western Chalukya court between 1031 and 1035 C.E. Around, 1042 C.E. the new ruler of Kalyani, Ahavamalla Somesvara I, with whom Vijayaditya VII allied himself, sent an expedition against Vengi. Rajendra Chola I sent Chola forces to Vengi under his general Rajaraja Brahmamaharaja. A bloody battle took place at Kalidindi in the West Godavari district. The result of the battle was indecisive. A lull prevailed in the warfare after this battle.
Rajadhiraja and Somesvara I:
Rajadhiraja Chola I (1042 - 1052 C.E.), the son and successor of Rajendra Chola I, led an expedition into the Vengi country in 1044 - 1045 C.E in order to reinstate the Chola ascendancy over Vengi to its former supreme state. He exchanged blows at Dhannada and obliged the Western Chalukyan army along with Vijayaditya VII to recoil in disarray. Later he entered into the Western Chalukyan authority and set fire to the Kollipaka fort on the frontier amid the Kalyani and Vengi territories. However, by 1047 C.E. Vengi and Kalinga were lost by the Cholas to the Western Chalukyas. They detained the territory approximately up to the closing stages of Virarajendra Chola`s reign (1062 - 1070 C.E.).
It is exceedingly unusual that Rajadhiraja Chola I unexpectedly lost concern in the Vengi affairs and by no means made any endeavor to restore his influence in the Telugu country. Rajaraja Narendra realised that to continue fight with the Western Chalukyas was futile and accomplished peace with Somesvara I.
Successors of Rajaraja Narendra
The demise of Raiaraja Narendra in 1061 C.E. presented an additional prospect to the Kalyani court to reinforce its hold on Vengi. Vijayaditya VII seized Vengi and with the sanction of his suzerain of Kalyani whom he served faithfully for numerous years, established himself enduringly in the realm. In the interim prince Rajendra Chalukya, son of Rajaraja Narendra through the Chola princess Ammangai was brought up in the Chola harem.
Rajendra Chalukya, also known as Rajendra Choda, married Madhurantakidevi, the daughter of the new Chola ruler Rajendra Chola II (1054 A.D. -1063 A.D.), the brother and successor of Rajadhiraja I. In order to restore him on the Vengi throne, the Rajendra Chola II sent his son Rajamahendra and brother Virarajendra Chola against the Western Chalukyas and Vijayaditya VII. The Chola military marched in opposition to Gangavadi and drove away the Chalukyas. Virarajendra then marched against Vengi and most likely slayed Saktivarman II, son of Vijayaditya VII.
In the interim, Rajendra II passed away and as his son Rajamahendra had predeceased him, his brother Virarajendra Chola went back to Gangaikonda Cholapuram and was crowned the Chola king. Fortunes oscillated for the Eastern Chalukya Rajendra Choda during this period. For sometime he ruled in Chakrakuta, while his uncle Vijayaditya VII was permitted to rule Vengi.
Vikramaditya VI
On the death of Somesvara I in 1068 C.E., Vikramaditya VI, one of his three sons, began pursuing his plans for securing the throne of Kalyani for himself. Consequently he first got Vijayaditya to create his submission to Virarajendra Chola and harmonize with him and followed the same course himself. Vikramaditya is the legendary king of Ujjain, India, famed for his wisdom, bravery and magnanimity. The title "Vikramaditya" has also been implicit by several kings in Indian history, remarkably the Gupta King Chandragupta II.
The name is a Sanskrit tatpurusha, (vikrama) meaning "valour" and Aditya, son of Aditi.
One of the most celebrated sons of Aditi, or adityas, was Surya the sun god; hence, Vikramaditya means Surya, translating to "Sun of valor". He is also called Vikrama or Vikramarka (Sanskrit arka meaning the Sun). Vikramaditya is said to have lived in the 1st century BC and may have been overpowered by the king Shalivahana. According to the Katha-sarita-sagara description, he was the son of Ujjain`s King Mahendraditya of the Paramara dynasty.
Nine Gems and Vikramaditya`s court in Ujjain
The Indian tradition asserts that Kalidasa, Vetalbhatt (or Vetalabhatta), Vararuchi and Varahamihira were an element of Vikramaditya`s court in Ujjain. The king is said to have had nine such men of letters, called the "nava-ratna" (literally, Nine Gems). Kalidas was the legendary Sanskrit laureate. Varahmihira was a soothsayer of distinction of the era who forecasted the demise of Vikramaditya`s son. Vetalbhatt was a Brahmin. He is identified to have accredited the work of the sixteen stanzas "Niti-pradeepa" (Niti-pradipa, literally, the lamp of conduct) to Vikramaditya.
Kulothunga`s Accession
Subsequent to the demise of Virarajendra and the assassination of his son and descendant Adhirajendra in the Chola capital, the Chola dynasty was deprived of a linear heir in the Vijayalaya Chola line. For three generations the Eastern Chalukyan princes married the Imperial Chola family and felt that they belonged as much to the Chola family as to the Eastern Chalukyan. Further, Rajendra Chalukya of Vengi, according to Kalingaltuparani, an epic printed in honor of Kulothunga`s incursion of Kalinga, `spent his childhood days in Gangaikonda Cholapuram and was a familiar favourite to the princes and the people of the Chola country`. It is under this state of affairs, Rajendra Chalukya moved into the `Political vacuum created by the death of Adhirajendra` and established himself on the Chola throne as Kulothunga Chola I. Since then Kulottunga I and his descendants were recognized as the Chalukya-Cholas in history.
Kulothunga I acquiescent himself with his uncle Vijayaditya VII and permitted him to rule Vengi during the enduring years of his life. With Vijayaditya`s death in 1075 C.E., the Eastern Chalukyan line came to an end. Vengi became a province of the Chola Empire. Kulottunga Chola I administered the province through his sons by sending them as Viceroys. However there was a prolonged fight between him and Vikramaditya VI over the possession of Vengi, which frequently changed hands. This perpetual struggle between the two great rulers ended in the Vengi kingdom slipping out of the Chola hands in 1118 C.E.