A brave man, that William Eccleshare. Just over four years ago, aged 49, he upped and left the relative comfort of his job as the European chairman of Young & Rubicam to take on the equivalent role at BBDO. It was a (relatively) scary prospect.
BBDO was comparatively new to the network game and was a disparate group of agencies whose original guiding lights were still influential. Most of its business (up to 80 per cent) was held on a non-network, often single-market basis.
So local managers, used to paddling their own canoes rather profitably, thank you very much, would have no call to listen to the likes of a William Eccleshare, would they? And what's more, leaving a senior role at a WPP-owned agency would surely prove a dangerous and emotionally unpleasant business.
And so it turned out (the latter prediction at any rate), with WPP seeking to hold him to a punitively long period of gardening leave. The stand-off, shamefully, got as far as the High Court and briefly threatened to drag the advertising industry into disrepute.
As Eccleshare prepares to move on again, a similar spat is unlikely, not least because BBDO's owners Omnicom plays by more civilised rules - but in any case, the prospect is somewhat academic, because this time he's jumping the fence to join the media owner side.
But still, it's every bit as scary a prospect. He's joining Clear Channel Outdoor to head up all of its international operations outside the US - and there could be troubles ahead. He's not just joining an organisation whose revenue prospects are cloudy (that's hardly unique these days) - it's also in a messy place currently as regards the bigger questions of ownership and finance at its parent company.
Has he, to be blunt and in the nicest possible way, taken leave of his senses? Well, no, of course he hasn't, he responds patiently - but slightly taken aback and more than a little hurt that anyone, even in jest, might question his judgment.
It is, he elucidates, the right opportunity at the right time - and Clear Channel, contrary to what we might have read recently in the press, can view the future with confidence.
"It's a great time to join a media owner," he says. "We're clearly at the bottom of the cycle and out-of home represents a fantastic growth opportunity. To take the helm of a major company with significant capital assets, with real strategic decisions to be made, is truly energising. If you have spent as long as I have in the business world, that's exactly the sort of challenge you want."
A challenge but also (some observers might feel) something of a gamble. In 2006, two private equity companies, Bain Capital and Thomas H Lee, borrowed heavily to help fund a $23.8 billion deal to delist the Clear Channel holding company and take it into private ownership.
In recent weeks there have been attempts to reapportion some of the debt - but the lenders (mainly US finance houses) have been unhappy at the proposals on the table and have been hinting that they'd consider forcing a crisis situation on the group if it continued to pay lip service to their concerns.
Not, in short, an entirely happy situation. Of course, the private equity angle means that Eccleshare's gamble will be hugely lucrative if it pays off - he will take up a substantial share option when he joins. And he'll be in a handy position to ensure that the value of that holding increases. His new patch - everything outside the US - has been targeted as a focus for growth. And digital (one of the recent success stories of his tenure at BBDO) is also expected to be a strong driver.
What's more, you'd be ill-advised to bet against him. He hasn't done too bad a job at BBDO, all things considered. His arrival coincided with the international network igniting the afterburners and going into overdrive - and it has been Campaign's Network of the Year in three out of the past four years.
He's a firm believer in light touch management - he's renowned for fostering teamwork without resorting to systems of command and control.
He's also a huge (some might say obsessive) Bruce Springsteen fan and marathon man in more ways than one. He not only runs them but he has the indefatigable stamina you need when you spend a good deal of your life travelling.
And last week, for instance, he managed to mix business with pleasure when he deftly arranged his schedule of meetings across the Scandinavian region to take in a Springsteen gig at the Stockholm Stadium. Colleagues say that, where The Boss is concerned, he likes to get all sweaty down the front, whatever that means.
And those colleagues will miss him. His departure is entirely amicable and he'll be continuing to fulfil his BBDO duties right up until he joins Clear Channel in September. Which is, all things considered, refreshingly different to the circumstances surrounding his last career move.
As Cilla Snowball, the chairman of Abbott Mead Vickers BBDO, puts it: "He's certainly played a part in making the network what it is today and he'll be missed. Making this sort of move shows he has a great deal of flexibility and a range of skills.
"He's a classic gentleman with brains - an accomplished, fair, principled operator and a great boss to work for. Everyone will wish him well."
Family: Wife Carol, children Thomas, Charlie and Rose
Favourite gadget: Ride-on mower
Most treasured possession: My grandfather's half-hunter watch and my
Interests outside work: Family, friends, government and politics.
Last book read: D Day: The Battle For Normandy by Anthony Beevor
Why Springsteen? Because "the highway's jammed with broken bones on a
last chance power drive ... We're on a journey together and the
destination doesn't matter"