During the middle Ages, knights used a Heraldic Coat of Arms to identify themselves. One man in armour looked a lot like another, so the Heraldic Coat of Arms was used to identify a knight in battle. In a society where few people could read and write, pictures were very important.
Keep Your Entry in Safe Position
A door knocker is an item of door furniture that allows people outside a house to alert those inside to their presence. A door knocker has a part fixed to the door, and a part (usually metal) attached to it by a hinge that may be lifted and used to strike a plate fitted to the door, or the door itself, making a noise. The struck plate, if present, would be supplied and fitted with the knocker.