Long before the doorbell, homeowners hung door knockers on their entrance doors. Door knockers have a long history -- they have probably existed as long as houses have had doors -- but it wasn't until the Middle Ages that door knockers became a fanciful house accessory.
Obviously, the purpose of a door knocker is to allow a guest the opportunity to announce his presence. During the superstitious Middle Ages, door knockers took on gruesome faces, such as gargoyles, dogs and lions, to ward off evil spirits from entering the home.
The Renaissance awakened an interest in art and design, and door knockers grew more ornate. Once constructed of pounded iron, knockers were cast in delicate shapes and figures in iron and brass for the doors of the wealthier members of society.
Door knockers are pervasive throughout history in every culture. The doors of the Cizre-Great Mosque in Anatolia, Turkey, built in 1160, hold two dragon bronze knockers. Ancient Italians hung Medusa heads. English doors sported snarling lions.