This composite photo illustration of images 650515622, 615846906, 650331660,651120206 shows British Prime Minister Theresa May (L) and President of the European Council Donald Tusk. British Prime Minister Theresa May has officially announced today March 20, 2017 that she will notify the European Union that the United Kingdom will leave the Union on March 29, 2017 triggering a 2 year negotiation period. (Photo by Getty Images)