A battle of massive proportions, the Battle of Azather was a strategic invasion of the Forerunner Stronghold and planet Azather by the Flood. Following their surprise attack on Mars, the Flood discovered the teleporter connecting Mars to Azather. Previous attempts by the Flood to attack Azather had been prevented by an energy shield of gargantuan puporsions, however the Flood gained direct access to a major Forerunner city from the teleporter.