“The Forerunners were sophisticated above all other empires and powerful almost beyond measure. Our Ecumene spanned three million fertile worlds. We had achieved the greatest heights of technology and physical knowledge, at least since the time of the Precursors...”

The Ecumene is the formal name of the galaxy-spanning Forerunner empire which existed over 100 thousand years ago and consisted of three million or more planets.[2] The political center of this empire was known as Maethrillian, a massive structure containing multiple cities.

Known worldsEdit


  • "Ecumene" is a word describing the Earth as known by the classical civilizations of Greece and the Romans. This later became used by Christian denominations to refer to the general "Christian world."
  • Even though the Ecumene council could have numbered into the hundreds, there seems to be three main speakers; the Ur-Didact, The Librarian and Faber, who represent the Warrior-Servant caste, the Lifeworker caste and the Builder caste respectively. 
  • All Forerunners in the Milky Way were part of the Ecumene, which would range in the billions.
  • The Ecumene was mentioned to be extremely wealthy several times.



  1. Halo: Cryptum - Introduction.
  2. Halo: Cryptum, page 9