The Sacred Band of Thebes, known also as the Theban Band, the Holy Children of Thebes, the Holy Legion or the Army of Lovers was a portion of the Theban army in the 4th century BC comprised entirely of male homosexual lovers.
The inspiration for such a force came from Phaedrus in Plato's Symposium :
"And if there were only some way of contriving that a state or an army should be made up of lovers and their loves... when fighting at each other's side, though a mere handful, they would overcome the world. For what lover would not choose rather to be seen by all mankind than by his beloved, either when abandoning his post or throwing away his arms? He would be ready to die a thousand deaths rather than endure this. Or who would desert his beloved or fail him in the hour of danger?"
Formed in 378BC by Gorgidas and later led by Pelopidas, the Army of Lovers numbered 300 at the Battle of Tegyra in 375BC. Here, they faced and routed an army of between 1000 and 1800 Spartans. This is the first recorded battle in history in which the Spartans were defeated by an army of inferior numbers.
The only extant historical document recording the event is Plutarch's Life of Pelopidas. According to Plutarch, on seeing the superior Spartan force a soldier remarked "We are fallen into our enemies' hands" to which Pelopidas replied "And why not they into ours?"
The Army's most famous battle was at Leuctra in 371BC where they fought alongside regular Theban units in a total force of around 6-7,000 hoplites supported by 1500 cavalrymen. The Spartans fielded 10-11,000 hoplites and 1000 cavalry. The result was a decisive victory for the Thebans and turned the course of the Pelopponesian War. Ultimately, the battle marked the downturn of Sparta as the greatest power of the Greek city-states.
The Theban Band together with 35,000 Theban troops was ultimately defeated and destroyed by Macedonian forces under the command of Phillip II of Macedon and his son, Alexander the Great, at the Battle of Chaeronea in 338BC. The decisive factor is believed to have been the experience of the Macedonians and their new unit - the long-speared phalanx. A giant stone lion was constructed by the Thebans as a memorial to the Sacred Band in around 300BC and stands to this day. In 2002AD, a Presidential decree barred those with "psycho-sexual or sexual identity disorders" (including homosexuality) from military service in the Greek army.
The term "Army of Lovers" is seen, presumably via Plato, in Thomas Pynchon's Gravity's Rainbow. Pynchon describes the slogan "an army of lovers can never be beaten" graffitied on the walls of Red Berlin at the close of World War II. The pop group, "Army of Lovers" take their name from this Pynchon quotation.