Great Silence

A Period of Forgetfulness
The Great Silence was a 4732 years period after the Great Expansion of humanity, where the colonies completely lost contact with each other due to technical unpreparedness. The colonies were forced to begin from ground zero, and while many perished, many also thrived. All of them however had reasons to refuse to search for other colonies, be them ideological, political or just out of fear. Some of these colonies became outright totalitarian isolationist distopias, arresting or killing anyone who wanted to search for other humans. Some colonies did not lose contact with others, but instead willingly turned contact off. That would be the case for the colony of Vulkania, which did all of the previously mentioned deeds. The magma-filled world was the last one to start contact with other colonies, and also became one of the founding powers for the Northern Star Federation posteriorly.

Contact was started, however, when all but the most ancient connections to Earth or other colonies had been forgotten. Seeking for life in the stars, the most successful out of all the colonies, the peaceful world of Tarria started doing space research after almost 5000 years of stagnation.

Reconnection
When it was learned other colonies existed, the first one to enter contact with Tarria was the world of Ocenia, a world where humanity had to thrive via underwater cities after many natural disasters.

This discovery shaked both worlds, and both started quickly exchanging knowledge, discovering that not only were both worlds in their newfound space age, but also that their information and cultures largely coincided, meaning they all came from the same planet or culture.

From then on, more worlds were discovered and a revolution successfully overthrew the totalitarianism in Vulkania, meaning they shortly after entered contact with the other worlds.

Within a couple decades, the four planets had developed healthy cultural and trade relationships, and were thriving more than they had in centuries.

The Ravager Threat
Eventually, an alien race caught wind of this rapidly developing civilization, and decided to try and ramsack it.

The Ravagers, as they were called, were a people from the planet of Ravaagia and were extremely dedicated to combat and conquering.

With the threat of this newfound alien first contact, a man called David Armstrong Jr. called for an emergency union of all four planets to combat the Ravager threat. This led to the creation of the Federation of The Northern Star, called as such thanks to the large supernova that happened north of all the planets, symbolizing something that all planets had in common.

In 4732 After the Expansion, it is marked the end of the Great Silence, symbolizing a new golden age of advancement in technology and communications following the union of all human planets and the subsequent defeat of the Ravager threat.

Mentions

 * The Great Silence was not yet mentioned in any Everdream work.