SO, after months of conjecture over when – indeed if – the Prime Minister would trigger Article 50, the UK’s divorce from the European Union is officially under way.

The historic nature of this moment cannot and should not be underestimated. There was a genuine sense of occasion as the PM signed the letter, and again as it was handed to European Council president Donald Tusk by the UK’s ambassador to the EU.

For Brexiteers, this was a moment of triumph. Those who voted to Remain, meanwhile, watched with the heaviest of hearts; the shared peace and prosperity of the last 40 years dismissed, the economic, social and intellectual bonds broken once and for all.

This is certainly the end of the beginning, then. But that is perhaps all we know for sure, as the triggering of Article 50 does not provide any answers to the big, complex questions around the economy, trade or the constitution.

In her statement yesterday, Mrs May told MPs the day marked “the moment for the country to come together”. The truth is, however, that despite rhetoric about “shared values, interests and ambitions”, Britain is a more deeply divided country than at any time in living memory.

On Tuesday, Holyrood voted to seek a second referendum on independence, which only underlined the collision course already set between First Minister Nicola Sturgeon – who called the triggering of Article 50 a “leap in the dark” - and Mrs May, whose “now is not the time” mantra surely cannot hold forever. There is no easy compromise in sight.

In Northern Ireland, meanwhile, there is still no clarity around what Brexit will mean for its border with the Republic and the ramifications for the peace process.

England, moreover, appears increasingly divided between Remainers and Brexiteers, north and south, rich and poor, with large parts of the electorate focused on immigration above all else.

It is in the midst of this increasingly stormy weather that the UK Government enters negotiations with the EU. In her letter to the European Council, Mrs May talked in deferential, respectful tones of retaining a “deep and special partnership”.

The EU’s chief negotiator Michel Barnier could be forgiven for raising an ironic smile at this change in tact: earlier this week David Davis was still threatening loudly that no deal was better than a bad deal, despite widespread agreement among observers that such an outcome could be catastrophic for the UK economy.

Of course, as has been said many times, it is in the interest of both sides to put bad feeling aside and make compromises. But with free movement and membership of the single market off the table, agreement won’t be easy. As Mr Tusk pointed out yesterday, Brexit has brought other EU members closer together; this is unlikely to be good news for a Hard Brexit-focused UK that has few strong cards left to play.

“We miss you already,” Mr Tusk said rather poignantly at the end of his speech. At this, many in the UK who voted to remain in the EU, including 62 per cent of Scots, felt their hearts grow even heavier.