British Prime Minister, Theresa May, has signed the official letter that will invoke Article 50, starting the two-year process which will see Great Britain exit the European Union.
— UK Prime Minister (@Number10gov) March 29, 2017
May is expected to address the British public after the letter is hand delivered to the President of the European Union.
The exit of the UK from the European Union ends a 44-year relationship after a referendum was held last June in which the contentious decision to leave the EU won out.
Britain is expected to leave the EU by the end of March 2019.