Anthony Joshua will go toe-to-toe with Wladimir Klitschko for the IBF and WBA world heavyweight titles at Wembley Stadium in April. But cutting through the hype, just how big is this fight?
Nick Parkinson runs through everything you need to know about the much-anticipated showdown...
Wembley sell-out?
In terms of attendance, promoter Eddie Hearn hopes to be given permission to set the national stadium out for 90,000.
If tickets sell out, as expected, Joshua-Klitschko will match the record of 90,000 set by light-heavyweights Jock McAvoy and Len Harvey at the now demolished White City Stadium, London, in 1939.
It also will beat the 80,000 who saw the super-middleweight rematch between Carl Froch and George Groves at Wembley in 2014.
Pay-per-view potential
Joshua-Klitschko will not be on free-to-air television in the UK and will be seen by fewer people than Barry McGuigan vs. Eusebio Pedroza (18 million), Nigel Benn vs. Chris Eubank (16m), Benn vs. Gerald McClellan and Eubank vs. Michael Watson (both 13m) in the 1980s and '90s.
More recently, British heavyweight David Haye's non-title comeback against little-known Australian Mark De Mori in January attracted 3m viewers on free-to-air channel Dave in the UK.
With Joshua-Klitschko set to be shown on pay-per-view television in the UK, it will have to go all out to break the record for a boxing PPV event involving a British boxer (1.2m for Ricky Hatton vs. Floyd Mayweather in 2007).
If Joshua-Klitschko does 1.5m buys, as the promoters hope, setting a new British PPV record, it will bring in more than £25m and beat Froch vs. Groves II (900,000 buys), Lennox Lewis vs. Mike Tyson (750,000) and Frank Bruno vs. Tyson (660,000)
Floyd Mayweather's long-awaited fight with Manny Pacquiao in May 2015 got 1.15million pay-per-view buys in the UK.
Overseas rights for Joshua-Klitschko will be the biggest ever for a fight in Britain. German broadcaster RTL will pay £4m to show the fight, while U.S. broadcasters Showtime and HBO are vying to screen it for more than £1m. And then there is the rest of the world rights.
Big-money bout
Joshua-Klitschko is expected to make the biggest gross revenue for a fight in the UK, perhaps more than £40m. Froch-Groves II is the biggest grossing fight ever in Britain after bringing in more than £22m. Both Joshua and Klitschko are expected to earn more than Froch's £8m purse.
If Joshua-Klitschko makes around £40m in gross revenue, it will still be way behind the big fights in the U.S. such as Mayweather-Pacquiao (£318m), Mayweather vs. Saul Alvarez (£120m) and Lewis-Tyson in 2002 (£89m).
London-bound
The appearance of Klitschko on UK soil follows the visit of Gennady Golovkin -- arguably boxing's pound-for-pound No. 1 -- to London in September. The Kazakh defended his world middleweight titles against Briton Kell Brook and was the biggest overseas boxer to fight in the UK for at least a decade.
Klitschko, 41 in March, will start as a betting underdog against Joshua and may not hold the same star appeal as he did five years ago when he beat Londoner David Haye in Germany. Klitschko and Joshua are both outside the ESPN pound-for-pound rankings; Golovkin is at No. 2.