Explanation:

The Sangam period extended from roughly 400 BC to 200 AD (early Chola period before the interregnum), when the earliest extant works of Tamil literature were written.
The traditional accounts of Iraiyanar Ahapporul mention that there were three Sangams (I, II and III) held, which flourished for 9990 years at frequent intervals.
These were attended by over 8598 scholars. Sage Agastyar was the founding father. The Ahapporul commentary also mentions about their successive order and the deluges occurring during the intervals between them.
These Sangams or academies were patronized by 197 Pandyan kings. According to the tradition, of the three successive Sangams the first two belong to prehistory. All the three were held in the capital of the Pandyas.
As the capital was shifted from time to time, old Madurai was the headquarters of the first Sangam, and the second academy was held at Kapatapuram. Both these centres were washed away by the sea during successive deluges. The third Sangam was located in modern Madurai.