The cheese started being made on farms from about 1830, in the local Caerphilly area, and was popular with coal miners.
The cheese originated as a simple way to make milk last for longer, and was enjoyed as a snack by coal miners at work.
They preferred it because of its thick rind, which made it easy to transport and eat; its salt content, said to help replace minerals lost during hard physical labour; and the fact that it did not dry out below ground.
Traditional Caerphilly production began to decline in the Second World War, when cheddar became the British cheese of choice because it kept for longer.
There are two different ways of making Caerphilly. The first is the industrial method, which results in a young, dry and crumbly cheese.
The other is the traditional method, used by Mr Rowlands and Mr Thomas, which creates a moister cheese with more character.