From the 11th century onwards, all felons were simply executed (unless they could read and assert the right of clergy). This removed low IQ violent people, about 1% of low IQ males, per year. Besides saving the expense of jailing these people, it made the UK much safer for commerce. Somebody is recorded robbing a store at gunpoint, perhaps even shooting people, and taxpayers are supposed to support that idiot for 40 years? Nope.