Einheriar

The Einheriar or Einherjar were the fallen warriors in battles chosen by the Valkyries to reside in Valhalla with Odin, until Ragnarok. When the god Heimdall would blow his horn or trumpet Gjallahorn, these dead heroes would march with the gods (Aesir) to fight the frost-giants and monstrous offspring of Loki.

Only half of those who were chosen by the Valkyries went to Odin's hall called Valhalla. The half that Odin received, who had fallen in battle, became his adopted sons. They would follow his lead when Ragnarok arrived. The other half of the brave fallen warriors resided with the goddess Freyja in her hall, called Fólkvangar ("battlefield").