Battle of Thermopylae
From Halopedia, the Halo wiki
Soldiers during the battle employed spears, shields and swords. The 300 Spartans managed to successfully fight off the Persians.
By the 26th century, the story of the battle was cherished and well known. Dr. Catherine Halsey believes that the story is romanticized to the point of fanaticism. Nevertheless, she did invoke the idea of the story by naming the SPARTAN-II program after the Spartans in the Battle of Thermopylae.
Master Chief Petty Officer John-117 also references the battle during his service, such as when he compares the Massacre at Eridanus Secundus to the Battle of Thermopylae in response to Vice Admiral Danforth Whitcomb's comparison of it to the Battle of the Alamo.
List of appearances