Steve Ballmer's resignation as CEO of Microsoft signalled a turbulent time for the company coming to a head - but what really caused his sudden departure?

There's a whole list of swings-and-misses to consider: Windows 8 was struggling. Windows RT had flopped. Windows Phone was trailing iOS and Android as the runt of the mobile OS litter. The Xbox One was struggling to gain a PR footing against the PS4. The disparate factions of Microsoft were slamming into one another like warring companies rather than harmonious parts of a whole.

Something wasn't right with the company's strategy and even a new One couldn't fix it.

According to stories collated from anonymous Microsoft employees by Bloomberg, that came from a huge clash of both opinion and personality between Ballmer and the Microsoft board that came to a head when Ballmer suggested buying Nokia.

Nok-nok-Nokia on heaven's door

The fascinating piece casts Ballmer as a petulant CEO, who reportedly "shouted at a June meeting that if he didn't get his way he couldn't be CEO" when opposition to his Nokia plan was raised.

Many on the board were apparently against the deal and against Microsoft moving into hardware production, including company founder Bill Gates and now-CEO Satya Nadella.

The deal was too expensive and too complicated to be worth it, they said. But Nokia's Windows Phone deal was due to expire in February 2014. With that date looming, Nokia started hinting that it would start making Android devices causing Microsoft to start making serious overtures just before MWC 2013.

So Ballmer finally got his way with Nokia - but at a price. In August, shortly before the deal was finalised, Ballmer announced his retirement.

Of course, there's more to the story than just the Nokia deal - corporate mutinies and panicked staff shake-ups also played their part - head over to Bloomberg to read the whole twisted tale.