On Tuesday afternoon Prime Minister Theresa May signed the letter that starts the UK's formal exit process from the EU.
The document will be hand-delivered by a senior diplomat to EU chiefs, at which point Article 50 has been invoked.
May called for unity in a speech on Tuesday:
When I sit around the negotiating table in the months ahead, I will represent every person in the whole United Kingdom – young and old, rich and poor, city, town, country and all the villages and hamlets in between.
And yes, those EU nationals who have made this country their home.
It is my fierce determination to get the right deal for every single person in this country.
However, Remainers were less than positive about the letter writing photo opportunity...
... Or the lack of glee in Theresa May's face.
Here's the best of the Remoaning on Twitter, some went after the "pandering fool" line:
Others took a different route:
Some went for football references:
Early on Wednesday the pound tumbled against a range of currencies in anticipation of Article 50.
Sterling was down around 0.5 per cent at $1.2393, having on Tuesday briefly peaked above $1.26, which was a seven week high.
Sterling was also down against the euro, the Swiss franc and the Australian dollar.