Archein

The Archein were a race of highly technologically advanced beings from the Andromeda galaxy whose home world was 2.5 Million Light Years from the Sol System. (Star Trek: Odyssey, Star Trek: Hidden Frontier)

Culture
The Archein were lead by the Grand Majan. The Archein's faith focused on worshiping The Great Ones. One precept of their faith instructed followers not to take things by force from others.

Infiltration of Milky Way Galaxy
In 2384, the Archeins began a military conflict in the Milkyway galaxy through the use of an artificial wormhole, in order to colonize from their home in the Andromeda Galaxy. This invasion was conducted under the military command of General Morrigu and the leadership of Majan Seram. The intent was to colonize in the Milky Way Galaxy due to a growing singularity which threatened the Archein's home planet and its entire region of space. During 2384, the Archeins had captured at least two systems inside Romulan space.

Seram had deceived the leader of The Archein people and the Grand Majan, who was in poor health, to believe that the wormhole led the Archeins to an uninhabited region of space inside the Milky Way Galaxy. In truth, it opened into occupied Romulan space.

A joint operation of Federation and Klingon forces, with assistance from the Romulans, destroyed the Archein's artificial wormhole, Iliad. (Star Trek: Odyssey: "Iliad")

Remaining remnants of the Archeins remained in the debris field of the battle that took place between the allied Alpha Quadrant species and the Archeins. When the USS Intrepid answered a Romulan distress call in the field, members of its crew were found victim to an Archein prisoner processing facility. When the crew was rescued, the facility was destroyed. (Star Trek: Intrepid / Star Trek: Hidden Frontier: "Orphans of War")