Wednesday marked a historic day as British Prime Minister Theresa May announced that Article 50 of the Lisbon Treaty had been signed, commencing the formal process for Britain to withdraw from the European Union.

Britain is the first country in the EU in more than 60 years to seek a divorce from the union.

In her address to Parliament on Wednesday, May said, “There is no turning back.” Outside Parliament, mixed reactions marked the day as pro-EU protesters gathered and the world tries to figure out what the move will mean for the future of Britain.

Scroll through to see more scenes from the day.