From sky-high success to the depths of difficulty, from renaissance to renewed tumult, the 21 years of Retail Week’s life have been a rollercoaster ride for Marks & Spencer.

Back in 1988 the retailer was doing what it had become famous for – clothing and feeding Britain. It was doing it so successfully that it racked up profits of £500m that year.

Already present in overseas markets, Marks & Spencer bolstered its international operations with the US$750m acquisition of US menswear retailer Brooks Brothers. Back at home its first out-of-town shop opened near Cheshunt, Hertfordshire.

In 1991 company veteran Richard Greenbury became chairman. Greenbury, revered in the retail world, was to steer Marks & Spencer to unprecedented success and preside over its most painful period.

By 1997 Greenbury was making history as M&S became the first UK retailer to hit profits of £1bn – an achievement to this day only matched by Tesco. Marks & Spencer’s place in the sun looked unassailable.

In retrospect, however, there were already signs of Marks & Spencer’s impending fall from grace even during those best of times. The retailer bought 19 Littlewoods stores for £192m. But it soon became apparent that the deal was not delivering as hoped, as store refurbishment costs and other problems dragged down performance.

It was, in many respects, symbolic of the fact that Marks & Spencers was not as rock solid as it appeared. It was also a deal championed by deputy chairman Keith Oates who, along with chief executive Peter Salsbury, was to play a central role in Marks & Spencer’s implosion.

A year after the Littlewoods deal, Marks & Spencers was riven by a boardroom row that was to destabilise the business and undermine its unique place on the high street and in shoppers’ hearts. The war erupted in November 1998, after interim results showed that Marks & Spencers was losing its touch. Value clothing retailers and others were growing in strength and Marks & Spencer’s customers had not warmed to the latest lines, resulting in a slump in interim profits.

Two days after the results, Oates attempted a boardroom coup. He failed. Salsbury, who it then emerged did not get on well with Greenbury, was appointed chief executive and Greenbury moved into a non-executive role.

A profit warning came in early 1999 and in the middle of the year Greenbury resigned as chairman. By the end of the year tycoon Philip Green had taken his first tilt at Marks & Spencer.

Drastic action was called for, but that prompted a top-level reshuffle. Former Carrefour boss Luc Vandevelde came in as chairman in 2000, Green walked away, Salsbury quit and ex-Kingfisher director Roger Holmes arrived as head of UK retail.

For a while it appeared Marks & Spencer was getting back on track. The retailer retreated from continental Europe to focus on its core business, which was enlivened by innovations such as maverick fashion genius George Davies’ Per Una range.

But there was a feeling that, despite the headline-grabbing appointment of former Selfridges boss Vittorio Radice and the ill-fated Lifestore project, the scale of change was insufficient. In spring 2004, Philip Green once again came knocking on Marks & Spencer’s door with a £10bn takeover proposal.

Cue the arrival of Stuart Rose, regarded as Marks & Spencer’s “king over the water” and the man to lead the defence of Marks & Spencer. Accompanied by associates Steven Sharp and Charles Wilson, the former Marks & Spencer trainee and Arcadia chief executive promised to rebuild Marks & Spencer based on its traditional values.

The takeover battle was as entertaining as it was bitter and incidents such as Green and Rose’s push-and-shove outside the group’s Baker Street head office hit the news as much as the rights and wrongs of the bid.

Emerging victorious, Rose raised morale and steered a revitalised Marks & Spencer back to former glories. He bolstered the management team with hirings such as womenswear supremo Kate Bostock.

As well as putting a greater focus on the domestic business, he kick-started a wave of internationalisation and ramped up online services. There was speculation about a merger with Sainsbury’s and in 2008 Marks & Spencer was finally able to report once again the magic £1bn profit.

But by this year M&S faced difficulties as the downturn bit. Rose had also alienated City investors by becoming executive chairman and the group’s food performance came under fire.

Although Rose has no plans to retire until 2011, the hunt for a successor is already on.

The story of Marks & Spencer over the past two decades has been one of achievement followed by setback. It’s the same today.