Rajendra Chola II was born in around 997 CE as the 5th among the nine children of Rajendra Chola I and Queen Mukkokilan Adigal. King Rajendra Chola I had appointed Rajadhiraja Chola I as the co-regent during his reign, who in return appointed his brother Rajendra Chola II as the co-regent after succeeding to the throne.
In his early days Rajendra Chola II helped his father and brother conquer many territories like the kingdoms of Polonnaruwa and Ruhana in Sri Lanka and suppress a number of revolts of the Pandyas and Srivijaya.
Rajadhiraja Chola I was killed in 1052 CE in the battle of Koppam and Rajendra Chola II wore the crown on the battlefield.
The battle of Koppam was fought in 1052 CE between Rajadhiraja Chola I and the Chalukyan ruler Someshwar I who was also known as Trailokyamall (the conqueror of the three worlds). King Rajaqdhiraja Chola I died fighting on the battlefield and his brother and co-regent Rajendra Chola II was coronated. He led the Chola army and defeated the Chalukyan forces, avenging the death of his brother.
The Chola-Chalukya conflicts continued during the reign of Rajendra Chola II. Someshwar I, the Chalukya ruler of Kalyani sent a large army under Valadeva to avenge the defeat of Koppam. A battle was fought on the banks of the Muddakaru River in which the Chalukyan commander Valadeva was killed. The Chola army was led by Rajamahendra Chola. Another battle was fought at Kudalasangamam between Someshwar I and Rajendra Chola II in which the Chalukyas were defeated again.
When Rajendra Chola II ascended the throne, the Chola Empire was already very vast. It stretched from Southern India to Bengal and parts of Southeast Asia. Rajendra Chola II not only successfully maintained the territories but also added a number of others. After defeating the Chalukyan king Someshwar I, he undertook another expedition to Kalinga and Sri Lanka. He also captured a number of other provinces like Ayodhya, Kanyakubja, Rattapadi, and Kadaram.
Rajendra Chola II ordered for the expansion of the Ulagalantha Perumal temple during his reign. A crack had developed in the gopuram of the temple which was partly made of bricks. The new gopuram was built of black granite to ensure durability and five stupas were also built enclosing the veranda.
Rajendra Chola II granted the town of Ulakkaiyur to build a stone temple which came to be known as the Agastheshwar temple dedicated to lord Shiva. An idol of Somaskandar, a form of Shiva, was installed.
Rajendra Chola II also expanded the Veetrirundha Perumal Temple in 1059 CE.
Rajendra Chola II died in 1064 CE at Gangaikondacholapuram and was succeeded by his younger brother Virarajendra Chola.