The Honours go to the Pallavas and cholas :
1 )Simmavishnu ( 550–610 CE):
Even from the very beginning of his reign, simmavarman 3 was only the de jure ruler of the kingdom, the de facto ruler being his son and crown prince Avani Simha or Simhavisnu. It is probably on account of that the Pallankoyil plates of the king dated in his sixth year do not give any details regarding his political achievements. It was during Simmavarman 3 s rule, his son, Simmavishnu took on a southern expedition and he conquered the Cola country and annexed it to the Pallava kingdom. Simhavarman III had two sons, Simhavisnu and Bhimavarman. Of them, the former ascended the imperial throne at Kanchi after his father. Bhimavarman seems to have settled in Kambhujadésa .
The Kasakkudi plates mention that Simhavisnu vanquished “the Malaya, Kalabhra, Malava, Cola and Pandya kings, the Simhala king who was proud of the strength of his arms and the Keralas’’. All these kingdoms lay to the south of the Pallava kingdom and hence it is possible that they were subdued by Simhavisnu in the course of a single campaign.
Conquest of the Telugu Codas
The Pallankoyil plates also mention that the Pallava Simhavisnu conquer- ed another Simhavisnu and the latter has been identified with the eldest son of Nandivarman, the Telugu-Coda king. The same incident has been referred to in the Kasakkudi plates where it is stated that Avani Simha conquered another Simha. Thus Simhavisnu was able to bring the Tamil country under one umbrella and annex the Renadu kingdom.
But his attempt to extend the Pallava Sway over the Visnukundin area was checked by the then Visnukundin king Vikramendra-bhattaraka I. The Indrapalanagara copper plate inscription* of the Visnukundin king mentions that he gained a victory over the Pallava ruler Simha in S. 488 corresponding to A.D. 566.
Western Calukyas of Badami
When Simhavisnu was expanding steadily in the northwest the Western Chalukyas were expanding in South . The rivalry between the two powers of Kanchi and Badami started at this juncture and continued for another two centuries. In theirs troop movements towards each, the Chalukyas held an upper hand initially as evidenced in Mahakutta inscriptions but the Chalukya king eventually lost his life in the battle making the pallavas victorious in this hard fought battle. The rivalry was thrust upon the Chalukya successors Pulikeshin 2 , Vikramadhitya 1&2 , Kirthivarman and the Pallava successors Narashimma, Mahendra 2, Parameswara and Nandivarman 2 . He held the largest Pallava empire of all times.
2 ) Nandivarman 2 ( 730–797 CE):
Paramésvaravarman II after his death in the Vilande battle was succeeded on the Pallava throne by Nandivarman II Pallavamalla, a prince froma collateral branch of the Pallavas which was ruling Indochina from the times of Simmavishnu. He and his line of successors ruled the Pallava country for nearly two centuries til the end of the Pallava hegemony
During the reign of Nandivarman II, many important political events took place in south India, wiz., the disappearance of the Western Calukyas of Vatapi, the emergence of the Rastrakitas of Manyakhéta and the rise of the Pandyas of Madurai. At the beginning of the tenth century A.D., his descendants on the Pallava throne yielded subsequently to the aggressive ambitions of the Colas.
He was defeated by chalukyas, Rashtrakutas, Gangas and Pandyas and by his long tactical rule he defeated Pandyas and Gangas.
3 ) Paranthaka chola 2( 905–955)
He defeated Pandyas, Andhra, Lanka and Rashtrakuta but experienced a crushing defeat at the hands of the powerful Rashtrakuta ruler Krishna 3. His long rule strengthened the small chola kingdom to become an Asian power under Rajaraja and Rajendra and their successors
4) Kulothunga chola 1 ( 1070–1122CE ) :
He is actually from the chalukya clan of the cholas who ruled the chola country for nearly 100 years. He was a peaceful emperor.He presided over the disintegration of the large chola empire. He sent emissaries to Myanmar and China. His defeats and victories include the Chalukyas and Kalingas. He was raised in Malaysia. Chinese accounts regard him as a Malaya king who ascended the chola throne.