The United Kingdom formally leaves the European Union

At midnight Brussels time the United Kingdom ceased to be a member of the European Union. The country spent 47 years in the bloc and is the first to leave it.

A transition period will last until the end of 2020: Britain stays in the EU single market and customs union while London and Brussels negotiate their future trade relationship.

In an address to the nation, Prime Minister Boris Johnson called the moment "the dawn of a new era". Leave supporters gathered outside Parliament in London, while opponents held events in Scotland and Northern Ireland.

Brexit will also affect Britain's trade with third countries: London now has to conclude dozens of trade agreements anew.