He's been described as the best connected man in the business world. Allan Leighton’s the arch-moderniser who's led some of the UK's most well-known companies.

His career started at Mars Confectionery in the mid-70s, working his way up through the business over nearly two decades. But, it was in the 90s that Allan Leighton really made his name.

He moved to Asda in 1992, becoming Chief Executive four years later. There he was credited with a successful turnaround of the supermarket and oversaw its acquisition by Wal-Mart in 1999.

By the 2000s, Allan Leighton had left Asda to 'go plural', as he put it, and went on to take prominent positions in companies including Royal Mail, Co-Op, Dyson and lastminute.com. But late last year, the supermarket chain came calling again.

Mark Coles has been talking to his friends and peers to understand where Allan Leighton came from and what’s in store for him at Asda.

Production TeamPresenter: Mark ColesProducers: Nathan Gower and Sally AbrahamsEditor: Ben MundySound: James BeardProduction Co-ordinators: Maria Ogundele and Jack Young

Credits:Marketing Academy: Rene Carayol interviews Allan LeightonMars Maltesters, TV advert 1970s Walmart Rollback TV advert 1998 Asda Rollback TV advert