According to current knowledge, there is no scientifically based evidence for the existence of these kings of the Sangam period. The main source is the Sangam literature - particularly religious literature such as Periyapuranam, semi-biographical poems of the later Chola period, as well as the temple and cave inscriptions and the records left by medieval Cholas.
Please note that all dates can only be approximate, determined and compiled based on inscriptions on temples and other scientific sources. Some dates were chosen fictitiously by me in order to be able to show the corresponding person in the timeline. I would like to point this out separately for these people.