* Saints Cosmas and Damian: These are twin brothers, venerated as Christian saints. However, they lived in the 3rd century AD, not the 3rd century BC. They were physicians who practiced medicine in the Roman Empire. They are traditionally depicted as holding a medical book and a palm branch.
* Other historical figures: There could be other individuals named Cosmos and Damian who lived during the 3rd century AD, but without further context, it is impossible to know what they did.
If you have any further information about the Cosmos and Damian you are interested in, please provide more context, and I will be happy to help you research their lives and deeds.
