Brexit: Who will be the key negotiators for the UK and EU?
Britain's journey leaving the EU moves to a new step on Wednesday when Theresa May's Article 50 letter arrives at the European Council in Brussels.
Over the next two years Britain and the EU will thrash out the details of a potential Brexit deal - and shape the future of UK-European relations.
But who will be the main Brexit negotiators?
The UK
David Davis
Secretary of State for Exiting the European Union (Brexit Secretary) David Davis is responsible for the work of the Government's Department for Exiting the European Union.
This department is responsible for overseeing negotiations to leave the EU and establishing future relations between the UK and the bloc.
Appointed to the role in July 2016, Mr Davis helped get the Article 50 Bill through Parliament - allowing Theresa May to formally trigger Brexit - earlier this month.
The Haltemprice and Howden MP will now play a key role in delivering what Britain wants from negotiations.
He will have to work closely with Parliament and the devolved powers across the UK to ensure the Brexit process is as smooth as possible.
Sir Tim Barrow
Sir Tim Barrow is Britain's ambassador to the EU and assumes "overall responsibility" for the UK's departure from the bloc.
He only took up the position in January, having replaced Sir Ivan Rogers who quit after he criticised the Government's "muddled thinking" over Brexit.
As head of the UK's permanent representation to the EU, it is his role to ensure Britain's policies are explained to EU member states.
The former ambassador to Moscow, whose 30-year political career has included two prior spells in Brussels, will represent the UK in weekly meetings at the European Council in Belgium.
On Wednesday he arrived in the Belgian capital to deliver Britain's Article 50 letter, signed by Theresa May, to European Council president Donald Tusk.
Oliver Robbins
Oliver Robbins is the Permanent Secretary for the Department for Exiting the European Union - and will work closely with David Davis.
Mr Robbins' prime responsibility will be to support the department in the negotiations to leave the EU and help establish future relations.
In his role, he will help the Government to examine its options for future relations outside the EU, with Europe, and the rest of the world, as well as responsibility for the wider European and Global Issues Secretariat.
Mr Robbins is a seasoned civil servant.
Europe
Michel Barnier
Michael Barnier will be the European Commission's chief negotiator for the "preparation and conduct of the negotiations with the United Kingdom".
Mr Barnier will lead the Commission's side of discussions as dictated to him by the 27 heads of member states and his boss, Jean-Claude Juncker, as well as European Council president Donald Tusk.
His role, as he set out in a speech on March 22, is to "reach an agreement on the orderly withdrawal of the United Kingdom, and to prepare the way for a new partnership".
"We want a deal. We want to succeed by reaching a deal," he said. "Succeed with the British, not against them."
Didier Seeuws
Didier Seeuws is the European Council's chief negotiator for its special task force on the UK.
Mr Seeuws was appointed by Donald Tusk to coordinate the divorce talks with Britain on behalf of the Council.
There is, however, uncertainty as to whether the Commission, headed by Mr Barnier, or the Council will lead the negotiations with the UK - and if the roles of Mr Seeuws and Mr Barnier will conflict.
Sabine Weyand
Sabine Weyand is the European Commission's deputy chief negotiator for its special UK task force.
Mr Barnier's number two, the German will play a key role in discussions with Britain and help finalise the divorce deal.
Ms Weyand has vast experience in preparing world leaders for G7 and G8 summits and will be well prepared to represent the EU when Brexit negotiations begin.