The U.K. will trigger Article 50 of the Lisbon Treaty Wednesday, officially beginning its divorce proceedings with the European Union.
Here, CNBC gives a timeline of the next steps in this historic process:
March 31 – The other 27 EU countries will send their guidelines for the negotiations to the European Council in Brussels, which'll then draw them together in one draft document. This will be presented by council president Donald Tusk within 48 hours of the triggering of Article 50.
April 4 – The European Parliament will make a statement on Brexit. The chamber where European lawmakers sit and vote on legislation has the power to veto the final deal between the U.K. and the EU.
April 29 – Deadline for the remaining 27 EU countries to agree on and prepare a joint document outlining what the EU will be seeking in the negotiations. The 27 heads of state will convene in Brussels on this date to approve the final details of what they want and do not want for Brexit.
Immediately after the summit – The European Commission - the executive arm of the EU – will then take on what the 27 leaders agreed on and prepare the final document outlining the EU's rules for the talks with the U.K. The Commission has said that it will do so "immediately after the summit." The institution will then use the document to negotiate with the U.K. government, given that it is the Union's main negotiator.
May/June – Even with the guidelines ready from both the EU and the U.K., the actual Brexit talks have not yet begun. The green light for that will only come from the EU's foreign affairs ministers. At the moment, foreign affairs ministers have meetings scheduled for 16th of May and 20th of June. They could however schedule an emergency meeting between those dates to approve the kicking off of the talks.