Janet Penrose Trevelyan 
Italy in the Dark Ages [EPUB ebook] 

WHEN the Emperor Diocletian, towards the end of the third century A. D., set himself to reorganize the government of the known world, his stout heart may well have quailed before the magnitude of the task before him. The preceding fourteen years had witnessed a succession of six Emperors, some of them men of exceptional courage and ability, of whom three had been assassinated by their troops, one had been killed by the hardships of campaigning, another by lightning on the borders of Persia, and the last still remained to be dealt with and removed…