'The Iliad' Greek fancast
(Just in case Nolan decides to ruin tackle the Iliad next)
A note on the ages: Since the Iliad is set in the 10th year of the war, if we suppose that Helen was approx. 20 when she arrived in Troy, it makes sense why she'd be approx. 30 at the time the Iliad is set. Likewise, it makes sense for the big heroes to be in their 30s-40s-50s (i.e. Agamemnon and Menelaus are middle-aged). Liberties have been taken to the Gods, since it's almost canon that Zeus and Hera are shown as middle-aged and Aphrodite, Athena etc are portrayed as younger.
Agamemnon - Giannis Stankoglou
Helen of Troy - Yolanda Kalogeropoulou
Hector - Giannis Kakourakis (although essentially the Crown Prince - if we go with the semi-canon version of Hector as the first-born - he was the ruler of Troy due to his father's old age making him unable to reign)
Andromache - Evangelia Syriopoulou (Hector's wife and mother of his son. The mother figure in the Iliad and its most important heroine after Helen)
Kassandra - Daphne Patakia
Deiphobus - Vasilis Milionis (the greatest of Nestor and Hecuba's sons after Hector and Paris; after Paris' death he wedded Helen, either because he was forced to or because he abducted her)
Priam- Stefanos Kyriakides (although still the King of Troy in title, essentially his son Hector is the Regent)
Thetis - Konstantina Klapsinou (Achilles's mother)
Achilles - Nikolas Mpravos
Calchas - Grigoris Valtinos (He is the apostle of divine truth. His most powerful skeptic is Agamemnon himself. Before the events of the Iliad, at the beginning of the expedition, Agamemnon had to sacrifice his daughter Iphigenia to receive favorable sailing winds.)
Ajax the Great - Thanassis Patriarcheas (He plays an important role in the Trojan War, and is portrayed as a towering figure and a warrior of great courage, being second only to Achilles among Greek heroes of the war)
Diomedes - Markos Papadokonstantakis (Diomedes is regarded alongside Ajax the Great and Agamemnon, after Achilles, as one of the best warriors of all the Achaeans in prowess. These three were Athena’s favourite warriors)
Aeneas - Anastasis Roilos (Aphrodite's mortal son whom she tried to protect so as not to die in battle)
Patroclus - Vaggelis Kakouriotis
Aphrodite - Iphigeneia Pieridou
Athena - Fotina Papatheodorou
Ares - Emilianos Stamatakis
Dione - Emily Koliandri (Aphrodite's mother, who comforts her after she rescues Aeneas; her monologue in the Iliad shows how useless the war is and praises the bravery of the men in combat)
Chryseis - Klelia Andriolatou (In the first book of the Iliad, during the distribution of the booty, she was given to Agamemnon as a sex slave by unanimous decision, in view of his kingly office. He bragged that he preferred her as a bed-mate to his wife Clytemnestra, because of her figure, her grace, and her skill at domestic tasks.)
Briseis - Christina Mathioulaki (Her role as a status symbol is at the heart of the dispute between Achilles and Agamemnon that initiates the plot of the Iliad. She was described as a greater beauty than Chryseis)
Iphigeneia - Evgenia Xygorou (the daughter of Helen and Theseus according to some sources, she must be sacrificed so that the ships sail to Troy)
Clytemnestra - Chara Mata Giannatou
Tyndareus - Tasos Nousias (Helen and Clytemnestra's father; it is disputed whether he was still alive or dead at the end of the Trojan War)
Leda - Evgenia Dimitropoulou (Helen and Clytemnestra's mother; she conceived Helen and her brothers after mating with Zeus who had taken the form of a swan to seduce her; in the Iliad it's mentioned she committed suicide after her daughter left for Troy due to her shame)
(For the Odyssey GR fancast see here)