It's a huge day of international football for the Home Nations with some fighting for their Euro 2020 places and Anglo-Welsh bragging rights at stake.
Northern Ireland and Scotland are involved in play-off semi-finals at 19:45 BST as they bid for a spot in next summer's rearranged European Championship, while England and Wales - who have already qualified - face off in a much-anticipated friendly at Wembley.
After tonight, we could even be looking forward to a potential Northern Ireland-Republic of Ireland play-off final - which would be at Belfast's Windsor Park - although they both have to get through tricky away games before they worry about that.
Northern Ireland travel to Bosnia while the Republic visit Slovakia and victories for both in tonight's one-legged ties would set up a mouth-watering all-Ireland showdown for Euro 2020 qualification.
Scotland's task of progressing past Israel at Hampden Park has been made even more difficult by the absence of three players because of Covid-19.
Stuart Armstrong, Kieran Tierney and Ryan Christie will all miss the semi-final after the former tested positive, with a final against Norway or Serbia awaiting the winners.
Away from the Euro 2020 play-offs, England and Wales go head-to-head behind closed doors in a friendly (20:00 BST) that is expected to be no less competitive.
England won the last meeting, a 2-1 victory at Euro 2016, and have been victors in 67 of the 102 matches between the two sides, with the last of Wales's 14 wins coming in the Home International Championship in 1984.
- England trio out of Wales match
- When record numbers watched England v Wales
- Scotland trio out of semi-final
- Northern Ireland won't focus on Dzeko and Pjanic in semi-final
How do the play-offs work?
All eight semi-finals are on Thursday, with the four finals on 12 November (before Nations League double-headers). They were initially scheduled for 26 and 31 March before the coronavirus pandemic.
Northern Ireland and the Republic both qualified for the play-offs purely on the basis of being in Tier B of the Nations League. Both sides finished bottom after failing to win a game.
Scotland qualified on their own merits after topping their Nations League group.
They are bidding to qualify for their first major tournament since the 1998 World Cup. Their only two European Championship appearances were in 1992 and 1996, going out in the group stage both times.
Uefa has said home fans - but no away supporters - can occupy up to 30% of the ground's capacity if local authorities allow.
That means 2,000 Bosnian fans will be allowed to attend their semi-final against Northern Ireland.
Scotland's home game with Israel will be behind closed doors because the government is not allowing spectators into matches.
Slovakia has declared a state of emergency, meaning fans are unlikely to be allowed into their game with the Republic of Ireland.
Where can you follow tonight's action on the BBC?
Bosnia v Northern Ireland: Live on Radio Ulster & online; live text commentary on BBC Sport website & app and match highlights on BBC One NI at 23:20 BST
Scotland v Israel: Listen live on Radio Scotland & online; text commentary on BBC Sport website & app
England v Wales: Listen live on Radio 5 Live, BBC Radio Wales or BBC Radio Cymru and online; text commentary on BBC Sport website & app
Slovakia v Republic of Ireland: Updates on BBC Radio Five Live; text commentary and match report on BBC Sport website & app
- Body Image: Exploring how it defines the way we feel
- Black History Month: What We're Not Taught In Schools