In days of old, people cooked their food in the fireplace and hung meat and fish in the hearth to cure. Fireplaces had a practical purpose. However, as time went by fireplaces acquired an aura of status and luxury, and people would select all the items in their room to match it. The material chosen to build the fireplace - be it wood, sandstone or marble - depended on where the owners lived and how wealthy they were.
By contrast, hearth-plates originally are luxury articles, intended only for people of noble or royal descent. Early hearth-plates were decorated with coats of arms; later ones were decorated with scenes taken from the Bible or nature. Traditionally, though, hearth-plates have had a double function: to prevent the firewall from crumbling and cracking as a result of the high temperature, as well as to absorb heat and radiate it into the room.
The purpose of a firedog is to lift the burning logs off the fire floor, allowing air to circulate under them and the fire to burn more effectively.