From Hidden Frontier
Infiltration of Milky Way Galaxy
In 2384, the Archeins began a military conflict in the Milky Way 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, 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.