By Alastair Macdonald and Yves Herman
BRUSSELS (Reuters) - It's been two centuries since a British emissary arrived in Brussels bearing a dispatch of such historic portent but Sir Tim Barrow, Britain's new envoy to the EU, took it in his diplomatic stride.
The ambassadorial Jaguar in which he rode to the European Council on Wednesday morning bearing Prime Minister Theresa May's Brexit notification was certainly more comfortable than the warhorse that brought the Duke of Wellington's messenger to the city bearing news of victory at nearby Waterloo in 1815.
But if word of Napoleon's defeat transformed Europe, so too the modest six pages on Downing Street foolscap by which May set the clock ticking on a two-year countdown to departure from the European Union bear huge ramifications for the whole continent.
The trigger moment itself lacked great drama.
At 1:25 p.m. (1125 GMT), Barrow proffered the crisp, narrow white envelope to Donald Tusk, who chairs summits of EU leaders. The moment the former Polish prime minister grasped it, the provisions laid down for withdrawal in Article 50 of the Union's Lisbon Treaty were met.
"After nine months, the UK has delivered #Brexit," Tusk tweeted a few minutes later, referring to June's shock referendum vote. By then Barrow had left Tusk's office.
Barrow, a grey-bearded 53-year-old, was once "our man in Moscow" before being parachuted into Brussels in January after the abrupt resignation of his disgruntled predecessor; he had rubbed May's more fervent pro-Brexit allies up the wrong way.
Affable behind closed doors, Barrow has kept his thoughts to himself in front of the cameras in Brussels and made no exception on Wednesday, ensuring the voice of Britain on the great day was that of Theresa May in the House of Commons.
His arrival, well-worn black briefcase in hand, was greeted with unwonted media attention. But he strode purposefully across the red carpet saying nothing. With the letter delivery, which eschewed the 21st century diplomatic norms of email, scheduled for lunchtime, Barrow spent his morning on illegal drugs.
At any rate, that was one topic on the routine weekly agenda for the 28 EU national envoys whose meeting he attended. Known by its French acronym Coreper, Barrow will get used to not being invited to all their discussions, now that Brexit is under way.
His encounter with Tusk lasted just a few minutes. A brief chat between the two in Tusk's office, standing in front of two pairs of EU and British flags, was inaudible to the handful of news photographers invited to witness history being made on the top floor of the Council's newly opened Europa Building.
Commissioned in happier times when the EU seemed destined to go on expanding, it was no little irony that the first great moment of history witnessed by the building denizens call "Tusk Tower" should be the unprecedented shrinking of the Union.
The letter, in which May promised constructive negotiation but also pressed home demands for free trade, will join others in the European Union's document archives, to be kept, no doubt, for centuries to come. Deal or no deal, Britain will be out, barring surprises, at midnight after Friday, March 29, 2019.
As Tusk was at pains to note later in remarks to reporters, it was "not a happy day" for most Europeans, including nearly half of Britons. But across the road at a British-style pub, UKIP lawmakers were toasting their victory at a "Brexit Party".
Searching for words to sum up his moment of history, Tusk, a historian by training, seemed at a loss: "What can I add to this?" he asked. "We already miss you. Thank you and goodbye."
(Editing by Andrew Roche)