This is why the Roman generals in Britain built Hadrian's Wall. They knew it wasn't defensively useful for crap, but it kept a lot of trained soldiers far away

This is why the Roman generals in Britain built Hadrian's Wall. They knew it wasn't defensively useful for crap, but it kept a lot of trained soldiers far away from home stuck in a cold unpleasant land with people they did not view as civilized from becoming a dangerous idle mass of people.