By "established" do you mean "can survive on its own"?

As that is how i read it.


There will be a power struggle; either fast and sudden or a slow burn of unrest til a coup. If they are the biggest thing around expect them to be the center of a new empire (in a century if they don't have an outfitted army available).

Expect anything that can't be manufactured to become a luxury item. It educational books and teachers are available expect a sane and stable ruler to make education and defense top priorities. Even an established colony is still a colony so general living conditions will worsen without trade.

If access to the motherland is available trade will likely start up. Immigrants will also show up in the droves if life at the colony is perceived as better. A sudden increase in people is a given.

The reactions of the settlers themselves will vary. Loyalists won't believe thinking it as some mistake. (Depending on distance) the average man might not notice; if Britain (England?) disappeared on America in the 1700s it would of taken months to learn of it and years to get it confirmed by a reliable source.

On the flip side Rome was in decline for a long time. After it started it was easy to see and still easy to doubt (unless a body of sizable water was in your path you could spend a week and walk to a Still-Roman city/holding) so it was harder to notice in the short term but easier to confirm.