Brexit forced the EU to reconsider how it is made up and the balance of power. Five years on, Brussels watchers spoke to Euronews about their views on the UK's exit.
23rd June 2016 - the news the EU didn't want to hear.
The UK voted to leave.
That decision 5 years ago exactly changed Britain, but also forced a rethink for the European Union.
Half a decade later, Brussels watchers like Eric Maurice who is head of Brussels office at the Robert Schuman Foundation says power has shifted.
Speaking to Euronews, he said: "a lot of countries, small and mid-sized countries, lost their....not their model...but maybe their preferred partner inside the EU, a country that shared their view of economic cooperation, international trade. So I'm thinking of Netherlands of course, the Nordic countries and also central and eastern Europe countries. They had to rethink their position within the EU and their link to Berlin, to Paris and to Brussels."
The perpetual negotiations among the EU's member states in Brussels lost one, of what were then known, of the big three countries of influence.
Britain had always been seen as a counterbalance to France and Germany.
After years of negotiations on the exit deal between the two sides, Britain formally left the EU on January 31st 2020.
With the UK gone, more focus fell on the new troublemakers in the EU like Hungary and Poland who have been reprimanded for breaches of Rule of Law.
Jennifer Rankin, the Guardian's Brussels Correspondent, told Euronews that Brexit has also allowed the EU some freedoms which were not there before.
She said: "The UK had already become semi-detached from the EU even before the referendum, so that the big crises that really dominated the EU for the last year, for the period running up to the referendum, the eurozone crisis and the migration crisis, the UK was very much sitting on the sidelines with an opt out from the Schengen free travel zone. So it wasn't really involved in all these poisonous debates about how many asylum seekers would be taken in. And also the UK, as not as a non eurozone member, was not involved, or at least only in a very peripheral way in that debate. "
The EU has had to recalibrate itself after Brexit but the fears that other member states would follow the UK out are far from materialising.