As we emerge from Covid I have been enjoying the E55, because it is so nice and cosseting and comfortable, yet still not too big for the city. I love the way the fury of the Germanic barbarian tribes is always under your right toe, awaiting the next on-ramp. Those clever Germans, tweaking...

So said Caesar, crossing the Rubicon. By crossing this tributary of the Tiber, Caesar had committed an act of war; he was massively out numbered by Pompey, and looked unlikely to win the coming civil war. But he rolled the dice anyway – and today, we know him because of it. What does...