The United Kingdom European Union membership referendum took place on 23 June 2016. The vote came in at roughly 52% to 48% in favour of leaving the European Union.
The government tried to start negotiations with the EU before they had officially notified them of it. However, the EU refused to do so and the UK started unofficially building a picture of what they'd like it to be like.
On 29 March 2017, Article 50 of the Lisbon treaty was officially triggered, marking the official beginning to the Brexit process. It is still very ambiguous and quite a mystery as to how it shall leave, and what will be left of the UK afterwards.