The last period in which we count backwards. Once again those historians have hit the nail on the head (think about it) and
called it the Iron Age because people in England started to make things out of iron.
People also became more tribal, more aggressive, and valued possessions even more. But the writing was on the wall in 55BC, or at least on a wax tablet.
In 799BC, the estimated population of England (to the nearest ten thousand) was 800,000 people.