coals to newcastle

The phrase "coals to Newcastle" is an idiomatic expression that means doing something that is unnecessary or redundant. It originates from a historical context where Newcastle upon Tyne, in England, was historically renowned for its abundant coal mining and supply. Coal was so plentiful in Newcastle that it became an unnecessary and redundant act to bring more coal to the area. Therefore, the phrase "coals to Newcastle" is often used to emphasize the pointlessness of an action.