The Crimson Emperor

In troubled 6th century Byzantium, Phocas, a centurion scarred by personal tragedy, is driven by a powerful vision to take the throne to restore the Empire's blessings. He befriends a weapon-maker's son, Romulus Demantius, who saves his life in battle, and in turn he saves Romulus's. Hiding his plotting and subversion among the troops, Phocas raises a revolt, usurps the crown, and his malign influence spreads over the Empire like a suffocating darkness, seen through the eyes of several families.
His incompetent reign of terror and bloodshed in obedience to his deranged mission brings the Empire to the edge of military and financial collapse, inflaming bloody riots and violence across the land. Their ancient foe Persia seizes the opportunity and attacks with all its forces. Repelled by Phocas's madness, Romulus and his family escape to Carthage, where he joins a huge military expedition to retake the crown and release the Empire from Phocas's misrule.
Along the way, foes bring deadly harm to those he loves, leaving him devastated. A final sea battle sees Romulus brought to the point of death, with only the hope of his heart's desire to save him, even as the Empire turns to face a heart-stopping fate.