The fall of the Chola Empire was as dramatic as its rise and was a result of the usual suspect: poor leadership among the later Cholas. In addition, failure to completely eliminate rivals, particularly the Pandyans and to a lesser extent the Sinhala kings of Lanka, led to an unexpected and rather comprehensive defeat. But it was not always like that. Indeed, after the vast expansion of the Chola Empire and its administrative consolidation, several competent rulers such as Kulothuga Chola I and Rajaraja Chola II ascended the royal throne and held the Empire together. In fact, Rajaraja Chola II built the Airavatesvara Temple, another great example of classical Indian architecture.
Instead of being defeated in one fell swoop, which was quite impossible because of the vast Chola territory, it was bled by a thousand cuts, primarily from the Pandyas but also to a lesser extent from the Hoysalas, with whom they enjoyed a blow hot-blow cold relationship. The first chink in the armor came with the defeat of Chola king Kulothunga Chola III at the hands of Maravarman Sundara Pandiyan II in 1216 in Lanka. Together with their unlikely allies the Sinhalas, the Pandyans successfully drove the Cholas out of Lanka, thus losing an important province.
This defeat was compounded by a string of bad leaders. At one point, Rajaraja Chola III was even kidnapped by a local chieftain! Meanwhile, in the Kannada territory, the Hoysalas had allied with the Cholas but were really dependent on them, being held up by minor clashes elsewhere. The Cholas, being stretched by their allies, found it difficult to resist the Pandyans, who were blessed with a string of strong, able leaders including Jatavarman Sundara Pandyan. Basing themselves in the Tamil lands, they quickly took control of the Telugu lands north of it, holding the Cholas in a grand pincer.
Over decades, the Pandyans steadily amassed power and territory from both the Cholas and the Hoysalas. The Hoysalas for one severely underestimated the power of their forces and were chased away from the Tamil lands to the Mysore plateau by Jatavarman Pandyan. By the time Rajendra Chola III's empire was coming to and end, the Pandyans had overtaken the Cholas as the mightiest force in the region. Based on records, the Chola empire ended with him and there was no successor. By the end of the 13th Century, one of the greatest empire's in South and South-East Asia had ceased to exist.
So it has been written.