Agamemnon helped his younger brother Menelaus sack Troy, when the younger's wife, Helen, escaped to Troy with Paris. In all accounts, he was a ruthless and fierce ruler with great power. When Odysseus made the claim of not only knowing Agamemnon, but playing a major part in the sacking of Troy, he meant to intimidate the cyclops, or at least cause him to rethink any actions he might take. This claim was meant to show that he was a fierce warrior and that it would be foolish to underestimate him.
