The Eileithyian Tree was a massive willow which formed when Eris, the Goddess of Chaos, and Aegis, the God of War, combined Their essence to create a single seed within the Erisian Pyramid in the Mhojave Desert.
The tree that blossomed from this seed grew for many years in the Golden Dais of Creation, sustaining itself on the sea of primal chaos below as it grew among the assorted flotsam and jetsam of mortar, blood, bones, flowers, and compost. In more recent times the tree was uprooted by Aegis and two of His adventurer followers, Gamdol and Aztecia, and moved in secret to the Temple of War to better protect it from Indrani, the Lady of Sin.
For 139 years, the Child-God Pandemonium slumbered within its protective branches, recuperating from the horrors dealt to Him in the War of the Divine Child, during which He was kidnapped by Sartan and bound in a fissure beneath Mhaldor. Finally, on the 6th of Miraman, 466 AF, Pandemonium became sufficiently healed and emerged from His arboreal shelter, leaving the Tree to extend into the night sky and dissolve into countless shafts of varicoloured light.