The Lefan Imperium was founded in 4,000 BBY by the final union of the three major tribes of Lef. They wished to continue their warlike and offensive policy in space, with their primary goal being the conquest of the Xoret Cluster. After building up their navy, consisting of enormous bioships, an Imperium task force was sent to the planet of Auts, which had been charted by scientists a decade before.