Midway through second volume (Folio Society edition, 8 volumes) of Gibbon's History of the Decline and Fall of the Roman Empire. Man, some of that is pretty hot stuff. Gibbon's style makes for slow reading, and often the need to re-read sentences, and the plethora of (often somewhat similarly named) emperors (and co-emperors and whatnot) can make for some confusion. Chapters 15 and 16 (the last two chapters of Gibbon's original first volume) are worth the price of admission.
Edited to add, 10/9/14, now a hundred pages or so into Volume 3. Learning much about Julian the Apostate.
--Ken