When is it?
The biggest heavyweight boxing bout in recent memory will take place on Saturday April 29, 2017.
Where is it?
The IBF heavyweight world title will be on the line when Joshua and Klitschko go toe-to-toe at the home of football, Wembley Stadium, London.
The fight becomes the just the second boxing event to be staged at the national football stadium after Carl Froch knocked out George Groves in the pair's rematch in May 2014.
What TV channel will it be on?
Sky Sports Box Office will host the fight.
What time is it likely to start?
10pm, though that is likely to change on the night depending on how the undercard fights go.
What are the odds?
The bookmakers have got Joshua pegged as the favourite, four and a half months out from fight night.
Anthony Joshua to win: 2/5
Wladimir Klitschko to win: 15/8
Where can I buy tickets?
There may still be a few in the upper tier of Wembley. Best checking here.
Lennox Lewis believes Anthony Joshua has the ability to become an all-time great heavyweight - just not to the level that he did.
In only his 19th fight as a professional, Joshua will on Saturday defend his IBF title and bids to win the WBA belt when he faces Wladimir Klitschko in front of 90,000 people at Wembley.
Klitschko succeeded the retired Lewis as the world's leading heavyweight and, along with the titles, is fighting to reclaim that position against Joshua, widely considered the favourite.
Concerns persist that such a step up in quality may have come too soon in Joshua's career - and Lewis accepts the 27-year-old's lack of amateur experience could be a hindrance - but retains faith in his ability.
"Can he be an all-time great?" asked Lewis, 51. "Yes. Yes.
"He can do anything he wants. But saying it and doing it is two different things. We can say it but it's up to him to do it. Yes, the potential is there.
"Could he go on to be better than me? I don't think so. It's difficult for me to say another man is better than me.
"How I come to that conclusion is I look at my amateur career. I had an extensive amateur career which led into my professional career which allowed me to be better.
"He didn't have an extensive amateur career - it was only a short one. To me, there is a lot Anthony Joshua still needs to learn.
"As he goes on he will learn them but his trainers need to understand that too because each fight for him is a learning curve.
"You don't want to learn in important fights; you want to be prepared for them."
What are they saying?
In the press conference to mark the announcement of the fight, Joshua insisted he was unfazed by Klitschko's reputation and his condescending comments.
“I think Klitschko’s calculated. He’s called me ‘Little Bro’ from the day we were on Ringside, on Sky Sports, when we were probably never going to fight anyway. Now he says it and we’re fighting, I let it go over my head,” said the IBF heavyweight champion.
“Klitschko’s the first champion that I’ve fought. It is no problem. And this is where the respect comes into it. It’s fine. You could let ‘Little Bro’ get to you, but I don’t let it.”
— Telegraph Sport (@TelegraphSport) December 14, 2016
"I’m fine with all that stuff. He can call me little bro and all these things until the cows come home, and then I go and spank him out in a round it’s kind of irrelevant.
“I want longevity as a champion. I like Cristiano Ronaldo because of how long he has been around at the top level. You can’t do it once, you have to do it more,” explained Joshua.
— Anthony Joshua (@anthonyfjoshua) 14 December 2016
Joshua hopes victory over the Ukrainian will mark the watershed moment and herald the start of a new era in heavyweight boxing.
“It is the start of a legacy. I think if Wlad wins, he will say to himself ‘I’m still the big bro’ but if he loses he will realise that the torch is changing hands. It is a completely different era. This is the start of, God willing - win, a new legacy, a new division of new up-and-coming champions.”
Klitschko claims he is 'obsessed' with regaining the IBF belt that Tyson Fury took off him in November 2015.
The Ukrainian was set to face Fury in a rematch in Germany until the fight was postponed after the British fighter was deemed to be "medically unfit" to fight.
"The Fury defeat woke me up," said Klitschko, who has had 27 world title fights in total.
"After so many years I realised I was not as motivated. Maybe it sounds crazy, but it was good that I lost that fight and good that I'm the underdog for this one. It's nice being the challenger again. I have an adrenaline rush in my blood. I've been missing it. This time I'm obsessed."
— Telegraph Sport (@TelegraphSport) December 14, 2016
Tyson Fury was forced to give up his IBF title to mandatory challenger, Charles Martin, who then relinquished his belt to Joshua in a knockout defeat in April of this year.
Anthony Joshua travelled to Austria to train with Klitschko in 2014 but the two-time world champion is adamant the 20 rounds they sparred together will have little bearing on the outcome of the fight.
“Any person or sparring partner that got into my training camp, getting a feeling for it, learning: it’s fine, I want people to learn from it and I’m happy to share. It’s definitely good for him, because he saw how a top athlete and champion is preparing," said Klitschko.
— Klitschko (@Klitschko) December 14, 2016
“He definitely adjusted it to his preparations. I think he did learn a lot. I’m also trying not to stand still, and I’ve been observing how he’s training, and how he’s getting ready, and he definitely has a professional team that works for him, to make him as strong as possible.”
Klitschko admits he is aware of the danger posed by the 27-year-old Briton and maintains he will congratulate his opponent if he wins.
“Anthony: he is more than just 18 fights. He has more than just two title defences. I truly believe in his talent, he’s an amazing athlete and a good representative for the sport.
“If he’s going to win then I’ll congratulate him, and when I win I’ll help him to come back. I’ve done it a couple of times already.”