I recently got around to reading Peter Heather's Fall of the Roman Empire. It's an excellent read for the layman, and he poses some interesting debates for the historian. One interesting theory he suggests is that the Huns had an indirect (and earlier than usually assumed) effect on Rome as their migrations forced the Goths to rush the borders and clash with the Empire.
But my area of study is the 3rd Century crisis, and that's why I noticed an odd and unorthodox account of Numerian's death.
Everyone remembers the famous emperor Numerian, right? He's right up there with…well, don't feel badly. They don't teach much about the 3rd century in school because it was such a mess. Rome's borders were crumbling under the weight of Germanic invasions, and the empire was in a state of nearly constant civil war. Dio (as in Cassius, not Ronnie James) remarked that Rome had descended "from a kingdom of gold to one of iron and rust."
From the death of Alexander Severus in 235 to the coronation of Diocletian in 284, there were 26 confirmed emperors and over 50 usurpers (Gallienus succeeded in winning exactly one thing in life–he had as many as thirty). Approval by the Senate was an afterthought–the armies were the kingmakers for the empire, and their favorite generals were the only men deemed fit to rule.