Kastoreion
The "Kastoreion" was an imposing Spartan war ceremony before the conflict with the enemy. The soldiers lined up crowned, with their helmets and shields at their feet, and the leading king sacrificed a goat to the goddess Artemis 'Agrotera', Apollo 'Vadromium' and the Muses. At the same time, pipers played a paean (war hymn) in honour of the Dioscuri. The war paean continued until the completion of the sacrifices and the slaughtering ceremony by the seers. Then the warriors, wearing their shields and helmets, chanted loudly, all together, the special paean as they were heading towards the enemy. Finally, it is noteworthy that before the battle, the soldiers beautified themselves so as not to offend the Chthonic gods with their dishevelled appearance in case they died in battle.
Source: Vlasis G. Rassias, "Celebrations and sacrifices of the Greeks", published by "Open City", Athens, 1998.