Who invented the hair straightening iron?

The very first hair straightener was invented by a Parisian hairdresser, Marcel Grateau in 1872. He used heated tongs or rods for straightening and styling hair and, although the rods were heated, they caused much less damage to hair than previous methods used for straightening purposes. Presently, "marcel" is a term used to describe a particular hairstyling method.

The early straightening devices came with two flat metal plates that were attached to two handles, and a hinge mechanism was used to maneuver them for opening and closing the plates, just like modern hair straighteners. In order to heat the metal, the plates were kept in the fire or hot ashes.