The "will they, won't they" nonsense seemed to drag on and on. Manchester City insisted they wouldn't sell. Milan president Silvio Berlusconi called Balotelli a "bad apple." And yet, the move always seemed inevitable.
There were reports that Juventus would try to scupper the deal and whisk the immensely talented and sometimes troubled forward away to Turin, but in the end his heart won out, and Balo chose the black and red of the club he'd followed as a boy.
AC Milan now has one of the most fearsome—and youthful—strike forces in Europe. 18 months ago their dressing room resembled a retirement home, but since then Massimiliano Allegri and Adriano Galliani have set about rejuvenating the Rossoneri's flagging fortunes by placing their trust in young, exciting talent.
But now that they have all this youthful promise, just what is their best XI with Super Mario?
It's taken some time for the well-travelled Marco Amelia to find his place, but at 30 years of age, it seems that the former Roma keeper has finally staked his claim to a place in a top team.
Amelia is likely to continue to compete with Christian Abbiati for the Milan gloves, but the latter is now 35 and looks some way from being a top keeper. Young hopeful Gabriel recently got a call up to the national team with Brazil, but at 20 he might just be too young for Allegri to place his trust in just yet.
The lightening-quick Ignazio Abate is a Milan youth product and possesses a great blend of attacking and defensive qualities. His work-rate, pace and eye for a pass should keep Balo & Co. well-supplied up front.
The 26-year-old Abate is also part of Cesere Prandelli's renovation work in the Italian national team, so he'll already be well known to Mario.
Another Milanista, young Mattia De Sciglio is one of Italy's most promising full-backs. At only 20, he still has plenty to learn, but since being called up to the Rossoneri first team he's proven himself more than capable.
The Milan No. 2 shirt involves a burden of responsibility, having being worn by club legend Cafu, but the Italian looks like he has what it takes to make it his own.
De Sciglio is an all-round performer with a good turn of pace and excellent control. He has come in for some criticism, as he's very much a right-footed player and so far his driving runs and sometimes obvious crosses have come to nothing, with only the likes of Bojan Krkic and Robinho up front to get on the end of them.
With Balotelli, De Sciglio has an ideal target for his passes, and if he develops a left boot, the pair could be making Milanisti happy for years to come. He'll also be hoping to join Super Mario in the senior national team soon.
Philippe Mexes has not been without his problems since moving to Milan from Roma in 2011, but the immensely talented Frenchman must surely be a starter whenever fit.
The 30-year-old is an aggressive defender who also has the ability to make driving runs forward and is very comfortable on the ball, and with Abate and De Sciglio, provides yet another quick route for the ball to leave the Milan area on its way forward for Balotelli.
OK, a 37-year-old veteran isn't an ideal choice for Allegri's new look Milan, but the Colombian comes with bags of experience and has proved himself more than capable alongside Mexes.
Other options include Kevin Constant, a natural midfielder who is co-owned with Genoa and Cristian Zapata, another Colombian but on loan from Villareal.
Milan have the right of first refusal on the latter, and the former's co-ownership can be settled by Italian football's closed-bidding process, whereby the two clubs who own a player each submit sealed bids, with the highest one winning. But neither player's future at the San Siro is thus far secured and centre-back is one of the few positions where Milan have a real weakness.
Allegri's midfield has been in a state of constant flux this season, but Nigel de Jong seems like an obvious inclusion in any side with a front line like Milan's.
An old pal of Mario's from their time together at Manchester City, the combative Dutchman will provide ample cover in defence should De Sciglio and Abate choose to bomb forward with a ball for Balo.
Formerly of Ajax, Hamburg and the aforementioned Blues, de Jong has plenty of experience across Europe and has been capped 66 times for the Netherlands. His energy and work-rate will be key to keeping the tempo high for Milan—something Mario will need to thrive.
Every great Italian side needs a cultured midfielder, the sort that can pick out the unlikeliest of passes and unlock the forward line's potential. Riccardo Montolivo is just that.
The 28-year-old features regularly in Prandelli's Italy side and he and Balotelli will be perfectly used to playing with each other already. His deft touch and excellent passing range would be a perfect balance to de Jong's physicality and would make the Milan midfield extremely dynamic—something that can only help their new striker.
Antonio Nocerino is versatile, athletic and well-known to Mario as a part of Cesere Prandelli's national setup.
Alongside Montolivo and de Jong, the Naples-born midfielder can create a central line that has plenty going to offer. And at 27, he's only approaching his peak—meaning he's another member of this squad who should be good for years to come.
Kevin-Prince Boateng got power, pace and technical skill—everything he needs to play the trequartista role behind Balotelli. An energetic and creative player, the German-born Ghanaian is adaptable and can drift deep or roam farther forward depending on what Allegri needs.
They're both young, both prodigious talents and both two of the faces of the new, multi-cultural Italy. And they're good friends from their time together in the Azzurri jersey.
Stephan El Shaarawy is the obvious choice for a strike partner for Balotelli, and the pair of them should wreak havoc against Europe's best defences for years to come. If Allegri can get them working together consistently, this has the potential to be one of the football's great partnerships.
The time for talking is over. After a protracted transfer and a stint in English football that was as well known for its lows as its incredible highs, the young Mario Balotelli has to step up and become the truly great footballer he's threatened to be.
Having coached him at Inter and asked specifically for his transfer to Manchester, few know Balo better than Roberto Mancini. And it says a lot about the forward that his greatest supporter has also—at times—been the man he's clashed with the most. But if Mario can knuckle down and live up to his potential, Mancini will be right: Milan will have bought themselves one of the world's truly great players.