When did Mridangam come into prevalence?
There is no evidential document written or otherwise which states exactly since when Mridangam is in prevalence but in Hindu Mythology it is believed to have been played by escorts of deities.
It is said that Lord Nandi, escort of Lord Shiva was a master percussionist, played for Lord Shiva during his Taandav performance. Another belief is that Mridangam was created to inform about Lord Indra’s arrival when he wandered through the heavens on his elephant, Airavata. These beliefs have given Mridangam the name ‘Deva Vadyam’ or Divine Instrument.
As to the time when Mridangam was played by mankind it is considered to have come into existence more than 2000 years ago.