The Skanda sashti kavacham that we all are familiar with was written by Bala Devaraya Swamigal (a student of Meenakshi Sundaram Pillai). He has also written kavachams on each padai veedu of Lord Muruga. There is an interesting story behind why he happened to write the kavachams.

Once when Bala Devaraya Swamigal suffered from severe stomach pain, which was not curable by any medicine. However, he knew it was curable only by the grace of the Lord. Hence he proceeded to Tiruchendur to worship Lord Senthilnathar. It so chanced that it was the first day of sashti. The very sight of lord reduced his suffering.

After which Bala Devaraya Swamigal started to compose and sing the Skanda Sashti Kavacham. That we are familiar. He also compose kavachams on the other padai veedus (war houses) of Lord Muruga. Most of us are unaware of these kavachas.

Skanda sashti kavacham