Seeds of Earth by Michael Cobley

The human residents of Darien think they may be the only surviving remnants of humanity 150 years after they fled planet Earth as it succumbed to an alien onslaught. Their universe view gets turned upside down however when an envoy from Earth arrives with the news that humanity was saved from destruction by a major galactic player called the Hegemony. Things get a lot more complicated when it turns out that Darien is home to an ancient artefact of incredible power. The residents of Darien both human and indigenous are caught in the middle but can they do anything to survive the onslaught of powerful forces coming for their artefact? First book of a major space opera saga. I love this kind of stuff so don't expect an objective opinion. I think it is great.