Halo Alpha
Halo Alpha

This article is a stub. You can help Halo Alpha by expanding it.

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 was the formal name of the galaxy-spanning Forerunner empire which existed around 100,000 BCE and consisted of three million or more planets.[4]



The Ecumene was founded some time after the Forerunners violently decimated their former masters, the Precursors. This empire would eventually span over 3 million planets. The capital of the Ecumene was moved from Ghibalb to a massive planet-sized structure, called Maethrillian, when the planet was heavily irradiated by supernovas.

Human-Forerunner war[]

Main article: Human-Forerunner war

Humans and Forerunners battling during the Human-Forerunner war.

Sometime around 110,00 B.C. a planet in Forerunner territory was invaded by the Human Empire and eradicated life in order to stop the spread of the Flood. While the Flood was successfully driven back, the Forerunners misunderstood this as an act of aggression and retaliated against the Human Empire with war.

While the Humans were initially successful in the early conquest of Forerunner worlds, the Humans were forced to deploy most of its military in the ongoing Human-Flood war. When the Humans finally defeated the Flood, it's military was exhausted from the fighting. Even the capital of Charum Hakkor was cut off from the Didact's naval fleets. On Charum Hakkor, the Humans combined their technology with Precursor technology and constructed successful defenses against the Forerunner's attacking fleets. However, it took the Didact great effort to finally capture the capital. Despite this, the Humans were able to defend against the Forerunners for 50 more years before their eventual defeat.

In the defeat of the Humans, the Forerunners decided to dismantle every single piece of Human technology. Many humans were executed by the Ecumene, as they were viewed as violent and aggressive. Due to this event, the Humans were split into many subraces as a "punishment".

Forerunner-Flood war[]

Main article: Forerunner-Flood war

Many years later, the Flood began to attack Forerunner planets. This caught the Ecumene totally by surprise as they didn't detect the Flood before it started attacking. The Flood spread faster than it could be contained, so the Governing body of the Ecumene was forced to orbitally bombard Flood infested planets. The Flood began to continually beat the Forerunners and their fleets for over 300 years. Ecumene troops were ordered to don heavy armor to stop the Flood, but this too failed. Forerunners eventually started to capture and study the Flood, hoping to find a countermeasure, but found none.

An idea was brought up in the Forerunner civilization, that the only way to defeat the flood was to destroy it's food. And so began the construction of the Halo Array, a system of Halo's designed to wipe out all biomass. Initially, the idea to fire the array was rejected many times, as some rulers of the Ecumene thought this was going back on their sacred duty to preserve life. In the end however, as the Flood spread more and more, the Halos were given the order to fire and all life was eradicated and the Flood was contained. All remaining Forerunners fled the galaxy and the Ecumene crumbled.


After the Firing of the Rings and the exodus of the Forerunners. They left behind much of their technology behind. The capital of Maethrillian was rumored to have survived the war. The Halos and the Ark were also left behind. Later on, a race of San'Shyuum discovered the remaining Forerunner artifacts and built a Religion, and a vast empire with the Sangheili called the Covenant.


Natural Planets[]

Main article: Forerunner Planets

The Ecumene had over 3 million planets but a few of them are known. The Ecumene also had created a number of planetoid structures. One example of this would be the Shield World.


  • "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. 
  • The Ecumene was mentioned to be extremely wealthy several times.[citation needed]
  • The Ecumene's collapse was ironic, as the Humans were able to defeat the flood while fighting the Forerunners at the same time, but the more powerful Ecumene were unable to fight the Flood one-on-one



  1. Halo: Cryptum - Page 304
  2. Halo: Cryptum - Page 264
  3. Halo Waypoint: Universe - Forerunners
  4. 4.0 4.1 Halo: Cryptum - Page 9