After over two years of rumours, callouts, and campaigning, the mega-fight everyone has been waiting for has been confirmed: Floyd Mayweather vs Conor McGregor.

Mayweather has not stepped into the ring since September 2015 but will put his 49-0 record on the line against McGregor - the incredibly confident two-weight UFC champion who has never fought professionally as a boxer.

I'D KILL HIM IN LESS THAN 30 SECONDS

Back in April 2015, McGregor showed no shortage of confidence in his ability. In an interview with Esquire, he suggested a bout between him and Mayweather would not last long.

"I don't look at a man who's expert in one area as a specialist. I look at him as a rookie in 10 other areas. If you can box, what happens if I grab hold of your legs? If you put me face-to-face with Floyd Mayweather - pound-for-pound boxing's best - if I fought Floyd, I would kill him in less than thirty seconds. It would take me less than thirty seconds to wrap around him like a boa constrictor and strangle him."

HE TALKS A LOT OF TRASH

McGregor's comments did not receive a response from Mayweather until December, when the boxing icon suggested the colour of his skin meant he would never have received the acclaim the Irishman did for knocking out Jose Aldo in 13 seconds

"I don't really know the McGregor guy; never seen him fight," Mayweather told FightHype. "They say he talks a lot of trash and people praise him for it, but when I did it, they say I'm cocky and arrogant. So biased! Like I said before, all I'm saying is this, I ain't racist at all, but I'm telling you racism still exists."

YOUR LAST FIGHT BOMBED

McGregor was unimpressed by Mayweather's claims of racism, responding via Instagram: "Floyd Mayweather, don't ever bring race into my success again. I am an Irishman. My people have been oppressed our entire existence. And still very much are. I understand the feeling of prejudice. It is a feeling that is deep in my blood. In my family's long history of warfare there was a time where just having the name 'McGregor' was punishable by death. Do not ever put me in a bracket like this again. If you want we can organise a fight no problem. I will give you a fair 80/20 split purse in my favour seen as your last fight bombed at every area of revenue."

I'LL KNOCK MAYWEATHER'S HEAD CLEAN OFF

McGregor made more outlandish claims about what he felt the outcome of a meeting between himself and Mayweather would be.

"I'm pursuing that [fight] and no one can stop me from pursuing that," McGregor told GQ. "He's got a little head on him. Honestly, my fist is bigger than his head. I sleep people. I put people unconscious. I'm stating facts. If I hit that man, his head is gonna go into the bleachers. You understand that? If I crack that little head of his, it's gonna go clean off his shoulders and up into the bleachers."

HE SHOULD LET ME KICK HIS ASS FOR A LOT OF MONEY

After McGregor made history by becoming the first fighter to simultaneously hold titles in two UFC classes, Mayweather offered some candid thoughts on what the MMA star's next move should be.

"The difference between me and him is this: he has to fight. If I was him and I was smart, before I lose again in the UFC I'd let Floyd Mayweather kick my ass for a lot of money. It makes business sense. This guy said I'm a p***y, I'm scared, I'm a chicken. All 49 said the same thing and all the results were the same. So with that being said, if Conor McGregor really wants to fight me, we can make it happen. But is he blowing smoke up everybody's ass? We need to know."

Man, much respect to Floyd Senior still getting a few rounds in at the gym. I hope I can still train at that age. Respect.

NO MORE EXCUSES

Mayweather claimed he was out of retirement a March interview with FightHype and once again called on McGregor to sort out his issues with the UFC and finally put pen to paper on a contract.

"I'm officially out of retirement for Conor McGregor. We don't need to waste no time. We need to make this s*** happen quickly. Let's get it on in June. I don't want to hear no more excuses about the money, about the UFC. Sign the paper with the UFC so you can fight me in June. Simple and plain. Let's fight in June. You're the B side, I'm the A side. We're not here to cry about money. I'm tired of all this crying about money and talking about you want to fight. You blowing smoke up everybody's ass. If you want to fight, sign the paperwork, let's do it."

WATCH ME TAKE OVER BOXING

While ringside at a fight in New York last March, McGregor sounded off to reporters: "Watch me take over boxing, trust me on that. No one in this boxing game knows what's coming. Trust me on that. I'm going to step in there and shock the whole goddamn world. Trust me on that. Look me in the eyes, 28 years of age, confident as a motherf*****, long, rangy, dangerous with every hand. Trust me, I'm going to stop Floyd and you're all going to eat your words. The whole world is going to eat their words ... I am boxing."