How a tip from Lennox led the Spice Girls to world domination
He explained the Eurythmics star played an important but unheralded role in encouraging the chart-topping group to "ham up" their characters.
Fuller pointed out in a documentary for BBC Radio 2 that Lennox may not be too happy to have her formative role in shaping the band -- whose hits included 'Wannabe' and 'Spice Up Your Life' -- made public.
The group had distinct personas when they burst on to the music scene and were eventually dubbed Sporty, Baby, Scary, Ginger and Posh.
Fuller said: "Each of the girls knew who they were and in their own way tried to represent it but it wasn't strong enough, and probably the most significant thing that happened was when they met Annie Lennox.
"I'm not sure this story has ever been told and Annie might not thank me for telling it. But I think we were flying to New York and I sort of said I've just signed this girl group. And Annie was very interested.
"She said 'I want to meet them'. Almost directly she was the one who who got them to be louder and more brash."
Fuller has gone on to manage figures such as David Beckham, Andy Murray and Lewis Hamilton and has made millions from the Pop Idol franchise.