With the news this morning that the CEO of Sainsbury's, Justin King, is to step down after 10 years with the business, we take a look back on the career of a retail legend in an extended news feature.

Best before end?

Having grown into the largest grocery retailer in the UK in 1922, Sainsbury's saw success well into the second half of the 20th century. But in 1995 its shine started to fade as Tesco beat it to the top spot in the big four supermarkets for the first time. A year later, it reported its first fall in profits for 22 years and in 2003 Asda became the second largest retailer, pushing Sainsbury's down into third place. The company's failure to introduce loyalty cards, a lack of decision on whether to enter non-food retail and a confused customer message perpetuated this decline and the beginning of the 21st century it was clear that a drastic change in strategy was needed.

The once and future King

Raised just outside Birmingham as one of four boys, Justin King grew up wanting to be a professional footballer but when this dream failed to materialise he undertook a degree in business administration at the University of Bath, graduating in 1983 and beginning his career as a shift manager at chocolate manufacturer Mars. By 1990, he was launching Häagen-Dazs in the UK as managing director. He then moved over to Asda in 1994 and Marks & Spencer in 2001, where he was key in pushing its Simply Food concept to its current popularity.

Mr King joined Sainsbury's in 2004, replacing outgoing CEO Sir Peter Davis who had failed to stem the decline in the retailer's sales despite a massive investment in infrastructure. At this point, Sainsbury's was struggling to win back market share from its competitors and was largely seen as being "on its knees".

Making Sainsbury's Great Again

His first task was to launch a major review of the business, with a strong focus on the opinions of its customers, including sending out a direct mail to approximately one million customers asking them what they wanted from the company and what areas it could improve in. Following this, in October 2004 Mr King launched his flagship three-year turnaround campaign 'Making Sainsbury's Great Again'.

Hitting the ground running, Mr King quickly realised that a major overhaul of the entire company was needed and drastic measures would be needed. Cuts to head office employees, shareholder dividends and staff bonuses were immediately implemented, as was the recruitment of approximately 3,000 shop-floor staff and improvements in the company's supply chain.

Flawed IT and distribution systems brought in by the previous management benefitted from £12 million of investment and the appointment of former Safeway logistics expert Lawrence Christensen. Sainsbury's US arm was sold off that year and instead the chain invested instead in its convenience store estate in its home market. Mr King also decided to focus on fresh, good quality food as opposed to value.

And now...

It wasn't long before the improvements in distribution and supply chain began to pay off despite a decade and a half of under investment and by 2009 Sainsbury's had reported nineteen consecutive quarters of sales growth. Its success is, as they say, history. In its most recent results, Sainsbury's was the only supermarket in the 'big four' to increase market share at Christmas 2013.

Speaking of his success, Mr King says: "I have a phrase I use at work which is famous for being my catchphrase - it's 'we are where we are'. What I mean by that is that people come to meetings and say 'well if only we'd done this' and it's my way of saying can we stop that, because we can only change things in the future."

Justin King will leave the company in a much better state than he found it, with underlying profits having almost trebled, 10 million more customers in its stores and online every week and its employees very much at the heart of everything they do. (Currently, Sainsbury's is the only food retailer accredited to Gold Standard by Investors in People and has paid £520 million to its employees in bonuses since re-introducing them in 2005.)

The end of the reign

Mr King's surprise announcement of his retirement comes as the group has succeeded in fighting off competition from its budget rivals and is the second biggest supermarket in Britain. It is also reported that it may become the target of a takeover offer from the Qatari government later this year.

Announcing his retirement, Mr King commented: "This was not an easy decision for me to make, and in truth it will never feel like the right time to leave a company like Sainsbury's. It has been a privilege to have led the Company for the past 10 years and I am incredibly proud of our achievements in that time. It is the 157,000 colleagues that make Sainsbury's so special and I would like to thank them for their amazing efforts over the last decade in making Sainsbury's great again. I am confident that under Mike's leadership the business will go from strength to strength."

Although Mr King and Sainsbury's will now go their separate ways, this is a partnership that will go down in UK retail history very much in the same vein as Sir Stuart Rose and M&S, Terry Leahy and Tesco or Mark Price and Waitrose. Mr King has assured his place in the annuals of retail royalty.