Fire marks first appeared in England in the 17th century, created by the earliest fire insurance companies after the Great Fire of London. In order to prove that buildings were insured, these marks were created out of lead, cast iron, and tin to indicate which company held the insurance.
Later on, these fire marks also became used as decorations and advertising devices for insurance companies. American insurance companies began using them on their insured buildings as well. Now, these fire marks are extremely popular items for fire collections.