The letter gives us some clues about May's negotiating priorities.
The two sides will need to meet three key objectives by March 2019.
A board member of Germany's federal bank has warned Britain of the potential consequences of its exit from the European Union.
Can Britain's negotiations to leave the EU keep the spirit of free trade alive?
"If people want to have a bit of fun about how we dress, then so be it," May said.
Barnier warned the remaining 27 members of the EU would find it easier to cope with the fallout from such a scenario.
If Sinn Fein and the DUP do not form a power sharing government the U.K. may make the controversial move to rule from Westminster.
The prime minister will promote the 'great union of nations' of the United Kingdom in Scotland visit.
Leaders celebrate the union's 60th anniversary days before Britain begins the process of leaving the EU.
Future price rises are likely due to import costs, report warns.
Triggering article 50 will begin a two-year period in which the U.K. will negotiate any future relationship with the EU.
Prime minister criticizes Britain's Theresa May for standing in the way of a new independence referendum.
Both had fortuitous routes to power and assumed absolute authority over the matters of the day.
Davis also said his department had not assessed the economic impact of the U.K. leaving the EU with no deal.
The Belarusian leader speaks out against Brexit and nationalists within the EU.
The bill will now be sent to the queen for symbolic approval which could be granted as early as Tuesday morning, leaving May ready to start a two-year negotiation period.
Sturgeon said it was unlikely Scotland could get what it wanted from Brexit talks within the U.K.
PM Theresa May still needs laws passed to allow her to formally notify the EU of the UK's intention to leave.
The Russian delegation had suspended their involvement after disagreements following Moscow's annexation of Crimea in 2014.