carry coals to newcastle

The phrase "carry coals to Newcastle" is an idiom that means to engage in a pointless or unnecessary task, typically referring to a situation where someone is doing something redundant or supplying something that is already in abundance or easily obtained. It originates from the historical context of Newcastle upon Tyne, England, which was known for its extensive coal mining industry. As coal was plentiful and easily accessible in Newcastle, there was no need to import it, making the act of bringing more coal to the city unnecessary.