Reading Gibbon's "Decline and Fall" - Chaper X, which is mostly about the Goths

Almost entirely about the barbarians - mainly the Goths - with the deadly succession of shortlived emperors mere background detail. And this seems right - the real story is not the politics of the Empire's leadership, but the story of how the empire catastrophically failed to maintain the physical security of its inhabitants, the first duty of any state, as the eastern defences crumbled both north and south. It seems to me almost as if the Roman Empire collapsed at this point, the middle of the third century.