Although this novel was written in 1977 and is out of print, you can still find it used and for a reasonable price through Amazon and AbeBooks. It's the sequel, King In Splendour, that's harder to find and more expensive.
Warrior In Bronze follows Agamemnon from a young boy to his becoming king of Mycenae. Agamemnon is not a likeable person, as seen in the first chapter, when as a boy he lets his good-hearted brother Menelaus take the punishment meant for him. Atreus later confesses that he knew Agamemnon was guilty all along, but applauds his despicable nature and ruthlessness, and makes him his heir. This is just the first of many, many examples that the House of Atreus is all about dysfunctional family values.
Agamemnon is a lively narrator, though a typical Mycenaean blowhard in boasting about his various accomplishments, real or exaggerated. He does, however, experience a peculiar sense of foreboding about a certain red marble tub in the palace of Mycenae.
The novel's plot centers around Atreus's blood feud with his brother Thyestes. Both men are unlikeable, cutthroat, and ruthless, and as the outrages pile up, so do the casualties. Men, women, and children alike all suffer the price for their hatred, and only the strongest survive.
The infamous Thyestean banquet is depicted in the novel. Atreus's culinary faux pas is so chilling I almost felt sorry for Thyestes. Almost. Any way you cut it, he's still a skeevy, unscrupulous bastard.
Shipway was a British officer in the Indian Cavalry, so it's not surprising that his prose is best when he's describing battles and other adventures; there's no shortage of action scenes. Where he does not fare so well is in writing compelling, fully realized female characters. Agamemnon's mother Aerope barely registers except as a foolish, oversexed woman, his first love Clymene exists to be gruesomely murdered and avenged, and his first cousin/stepmother Pelopia is there to be frightened, doomed, and tragic. Clytemnestra, the one woman who makes her presence felt, and proves herself a match for Agamemnon, enters the story late in the novel, and her best scenes are actually in the sequel.
I do not agree with all of Shipway's ideas, especially the notion that all the Mycenaean scribes have an Israelite origin, thus explaining their literacy. Nor do I think that Mycenaean noblewomen went around bare-breasted all the time (this is a popular convention in the Mycenaean novels of Henry Treece, also). But Shipway does have some novel ideas about Mycenaean military tactics and politics. If you like novels set in the Mycenaean period, Warrior In Bronze is a classic, and its action and adventure scenes hold up very well.