Chola kings were very powerful and conquered up to Cambodia.what happened to their descendants?

After the reign of Rajendra chozha, their successors are incapable and the dynasty started diminishing. Pandyas and pallavas grown in a side as well as threats from Muslims, Marathas, Nayaka's (from Andhra pradesh) supported their fall. Apart from that, the fight between the cousins paved the way for their exit.

Cholas degenerated and became weak. It fell into the hands of their enemies. Tanjore, after the Cholas was ruled by the Marathas, Nayakas, and the British.

The rise of Vijaya Nagar will tell us all the three dynasties,Chera,Chola and Pandiya were not in their ruling positions.You can have a clear account about these southern dynasties in Dr.Surya Narayana Rao's book titled "The unforgettable Empire".This book is available in Hampi and Amazon.com.

Like any dynasty, generations later power ruined them and they just went into oblivion

they r ruling cambodia right now!!