Background Aditya I had two sons namely Parantaka I and Kannara Deva. The eldest son was Parantaka, born to a Chera wife; the youngest son was Kannara Devan, born to a Rashtrakuta wife. After the death of Aditya I, Rashtrakuta king
Krishna II tried to exert his influence in the Chola country by placing his grandson Kannara Deva on the throne.
Battle of vallala In 907 CE, Parantaka became the king. Disappointed by this,
Krishna II invaded the Chola country. On Rashtrakuta side, prince
Indra III lead the battle, while the Chola side was led by King Parantaka and Prince
Rajaditya. In the year 911, in the
Battle of vallala, a large number of Rashtrakuta soldiers died and their army began to weaken. Krishna II withdrew and his forces retreated. The Cholas advanced further and attacked the Rashtrakutas and chased away from their territory. Eventually the Cholas defeated the Rashtrakutas. Parantaka Chola's early series of victories would also includes this Rashtrakuta War.
Conflict with Rashtrakuta feudatories Banas and Vaidumbas During the early phase of Parantaka I’s conflict with the Rashtrakuta Empire and its allies, campaigns were directed against the Bana and Vaidumba chiefs. According to K. A. Nilakanta Sastri, the Bana rulers Vikramaditya II and his son Vijayaditya III were defeated in these campaigns, leading to the incorporation of Bana territory under Chola control, at times administered through loyal subordinates. The Vaidumbas, who were associated with the Banas, also appear to have been reduced to submission during this period, with some chiefs seeking refuge in Rashtrakuta domains. These events are generally placed in the early decades of Parantaka I’s reign.
Against Nolamba king Iriva Nolamba Diliparaja During the 29th reign of Parantaka I, Chola influence appears to have extended into regions near Nolambavadi. A Kannada inscription dated to his 29th regnal year (c. 936 CE) of parantaka I, found at Bairakur in present-day Karnataka, indicates a possible conflict between Parantaka I and the Nolamba ruler Iriva Nolamba Diliparaja, a feudatory of the Rashtrakuta Empire. While the evidence is not conclusive, some historians suggest that this encounter may have ended in favour of the Cholas, pointing to a possible success of Parantaka I over a Rashtrakuta subordinate.
Initial encounter with krishna III Some historians note that the struggle between Parantaka I and the Rashtrakutas was not uniformly favourable to the latter. The Kanyakumari inscription of Virarajendra states that Parantaka I defeated Krishna III. Historian A. S. Altekar interprets this reference as possibly relating to an earlier engagement prior to 944 CE, suggesting that Parantaka I achieved a temporary success against Krishna III before the renewed Rashtrakuta invasion that culminated in the Battle of Takkolam (c. 949 CE). K. A. Nilakanta Sastri also questioned the early dating of the Siddhalingamadam inscription attributing the conquest of Kanchi and Tanjavur to Krishna III in 944–45, arguing that firm Rashtrakuta occupation of Tondaimandalam occurred only after the Battle of Takkolam. == Civic and religious contributions ==