Britain filed for divorce from the European Union on Wednesday, with fond words and promises of friendship that could not disguise the historic nature of the schism — or the years of argument and hard-nosed bargaining ahead as the U.K. leaves the embrace of the bloc for an uncertain future as "global Britain."
Prime Minister Theresa May triggered the two-year divorce process in a six-page letter to EU Council President Donald Tusk, vowing that Britain will maintain a "deep and special partnership" with its neighbors in the bloc.
"This is an historic moment from which there can be no turning back," May told lawmakers in the House of Commons, moments after her letter was hand-delivered to Tusk in Brussels by Britain's ambassador to the EU, Tim Barrow.
In response, Tusk told Britain: "We already miss you...There is no reason to pretend this is a happy day."
But for all the warmth, the next two years will be a tough test of the notion that divorcees can remain good friends.
Here are some key reactions and commentary following Britain's launch of the process to leave the EU:
'Interlinked relationship'
"The negotiations must first clarify how we will disentangle our interlinked relationship... and only when this question is dealt with, can we, hopefully soon after, begin talking about our future relationship," - German Chancellor Angela Merkel.
'Let's stay friends'
"The sentence often used in private divorces, 'let's stay friends', rings true in this case. Britain remains our neighbour, like the European Union is for Britain. We need each other" - German Foreign Minister Sigmar Gabriel.
'Sentimentally painful'
While Brexit is "sentimentally painful" for the Europeans, it would be "economically painful" for the British. But "it is not our intention to punish (the British) for the principle" - French President Francois Hollande.
'Act as one'
"In these negotiations the Union will act as one and preserve its interests" - the EU's other 27 member states.
'New chapter'
"Today isn't a good day. #Brexit marks a new chapter in our Union's history, but we're ready, we'll move on, hoping UK remains (a) close partner" - European Parliament chief Antonio Tajani.
'Building new walls'
"The politicians who fought for #Brexit were allowed to grow up in a free Europe. Today they are building new walls... History will show that Brexit is a tremendous mistake. It will create a lot of damage for both sides." - Manfred Weber, head of European People's Party (EPP), the biggest group in the European Parliament.
'Door schtill open'
"Dear Brits, ze door is schtill open" - German daily Die Welt, in accented English.
'Point of no return'
"The impossible dream is happening. Today we pass the point of no return," - former UKIP leader and prominent "Leave" campaigner Nigel Farage, who tweeted a picture of the letter being handed over with the phrase "you've been triggered."
'Avoiding a divorce'
"The Netherlands are committed to avoiding a divorce and building another friendship" with Britain. "We want to prevent others from awarding themselves the biggest parts of the cake... Let's stay calm, be realistic and negotiate" - Dutch Foreign Minister Bert Koenders.
'Netherlands will follow'
"A historic moment! Congratulations Britain, regaining national sovereignty! The Netherlands will follow in a few years time!" - Dutch Freedom Party MP Geert Wilders.
'Path still unknown'
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