It's difficult to categorize "The Grass Crown" as a sequel to Colleen McCullough's first novel of ancient Rome, "The First Man in Rome." It's more of a continuation of an epic, which is the collapse of the Roman Republic, due in no small part by the great weight of the titans striding across Italia in those days.
Where "The First Man in Rome" left off with Gaius Marius ascendant, thanks in large part due to the savage cunning and brilliant audacity of Lucius Cornelius Sulla, his right-hand man, "The Grass Crown" starts with these two friends growing apart. Their closest friend, Publius Rutilius Rufus, whose letters offer some of the most entertaining passages in the first two books, notes the growing rift between the two even at a pleasant dinner party. This gap is a sad foreshadowing of the chasm that will soon develop between these two.
Neither Marius nor Sulla is equipped to be second best at anything, and even though they share many traits, these two are too different to remain friends for long. Marius, even though he has suffered a stroke, remains convinced that he is the best general in Rome and is just insecure enough to need to prove it. Sulla, chafing at Marius's position as the First Man in Rome, is desperate to prove his place and to restore the patrician class (which Marius has undermined with his New Man successes and radical ideas).
Tragedy ensues as Sulla loses his beloved son and Marius suffers an even more debilitating stroke -- although this does bring the young prodigy Julius Caesar to Marius's side as an aide. Marius's insecurity becomes palpable when he grows resentful of the staggering potential demonstrated by Young Caesar.
Marcus Drusus, another hold-over from "The First Man in Rome," gets caught up advocating for the Roman citizenship for all Italians . . . this sounds odd to folks who aren't familiar with Roman history, but "Italy" as we now understand it is a modern invention. By advocating the extension of citizenship to all Italians, Drusus creates a firestorm among the Roman political class (the Romans were a remarkably arrogant people, and looked down with disdain even on those Italians who fought side-by-side with them against the dreaded Germans). This conflict drives much of the book, and its fall-out creates the military conflict that drives the book to its conclusion.
Both Marius and Sulla get involved in the Roman military campaign against the Italians, and Sulla manages to win the coveted Grass Crown, one of the highest awards in the Roman world. But still, Sulla feels eclipsed by Marius, and soon these two giants are at war. Sulla, violating centuries of precedent, leads his armies against Rome, and the bloody fall-out of Roman fighting Roman is almost too much to bear.
Through it all, McCullough writes with her usual straightforward brilliance. Rather than dazzle the reader with literary flourishes, McCullough paints an exhilirating world through precise descriptions and vivid characterizations. Her grasp of the scope of the Roman world is staggering, and her glossary and maps are invaluable.
Fortunately, McCullough pays as much attention to the female world of Rome as the male -- we get a fully realized Rome that reveals the political clout of the Roman woman even in a world that officially denied her so much power.
All in all, a heck of a read. However, this book really must be read after "The First Man in Rome," or you'll miss too much of the back story.