Again, this is a review of a book that I bought and read long ago (in 2005), hugely enjoyed, but didn't bother to review at the time. Contrary to other reviewers, I found Tyrant, the life story of Dionysios the Elder of Syracuse, to be Massimo's best book, probably because this is essentially a historical novel with little fiction in it and because Manfredi obviously knows his topic well.
The basic story is about the descent of a young (but rather ambitious) man from a good family of Syracuse (although not among the highest aristocratic families) "into a merciless despot", as another reviewer puts it. However, this is certainly not "the story of Dionysios written by Dionysios" for, despite all the facts explaining why he becomes such a despot, I certainly did not get to sympathize with him. Another interesting character, presented as a contrast to the Tyrant and who, unlike him, has not put aside his initial idealism, is that of his brother Leptines.
I won't go into too much details and spoil the story by summarizing it. The only thing I can see is that since Dionysios became tyrant on the basis of his abilito to win the war against Carthage, the book is full of battles and sieges, as one war follows another. Another element is that Valerio Massimo Manfredi paints a picture of Dionysios which I belikeve to be much more convincing that the one that you find in the historical sources which almost unanimously blacken his nale and put each and every of hos actions in the most unfavorable light they can come up with. I do agree that Manfredi's book does show some csympathy for his main character at times and does largely omit some facts - such as his efforts to appear as a great poet and philosopher - which mke him more ridicule than anything else since he seems to have been rather untalented in this respect. However, his paranoļa and cruelty, however justified, are rather well described. Some elements may be missing from the book, especially regarding the relations among and within Sicilian cities at the time - the so-called "stasis" or social conflicts between oligarchic and "democratic" factions that often lead to civil war.
Anyway, to learn more about this period, the most accessible book is Jeff Champion's first volume on the Tyrants in Sicily. It has some limitations, but it certainly is a useful addition to this book if you are looking for more historical context. So, four stars, but not five.