Like Williams' Theodosian work, this book is an easy read that more or less sums up what previous scholarship without new analysis. It's a good introduction to the period but not on par with biographies of other emperors such as Constantine and Julian.

This is a well-written, fact-filled book that should be considered a must-read to any serious student of the Late Roman Empire. Diocletian has been given scant attention by Classical scholars but his stabilization of the Empire was vital for two reasons: it preserved the entire Empire for nearly 170 years after his retirement and laid the foundations for the Eastern Empire that survived until 1453 c.e.

There is also great attention given to Diocletian's separation of himself as Emperor from the Roman Army and Roman politicians. Williams lucidly points out this is the beginning of Western Civilization's "Divine Right of Kings," and the foundation of Medieval kingship. Diocletian established this separation order to secure his personal safety.

Diocletian's retirement is also given considerable attention. His retirement palace at Split is discussed in some detail. Also, the attempt of Galerius and Maximian to drag him back into politics, which he completely refused. Finally, the rather sad depiction of him as a marginalized relic who had to ask old army friends for favors in order to help secure temporary safety for his family (who were eventually murdered).

This is a great book but its great detail may overwhelm the arm-chair historian. Williams deserves many cudos for his work in bringing about the first English biography of Diocletian in some time.

As Williams recalls, the Third Century was almost an utter debacle for Rome. The frontiers disintegrated, the coinage collapsed and the political system imploded. Diocletian's reign (284-310) mitigated the disaster. His reforms completely saved the East, and gave the West another good 100 years. He broke the cycle of assassination-civil war-assassination that had marred the principate; he created a "Tetrachy" of four mutually dependent co-emperors and he refashioned the imperial defense structure. Borders were restored, and although his attempts at price control failed, his economic reforms were broadly successful. He is widely thought to have had the luckiest death of any Roman Emperor, dying in retirement at his cabbage farm. If you want to know about Diocletian, his life and times, you need go no further than William's masterful account.