If the first rule of business is know your customer, then the second should be know your chairman. This simple oversight came back to haunt the board of Smith & Wesson, America’s oldest gun maker, when it emerged in early 1994 that its newly appointed chairman of just one month had served more than 15 years in jail for a string of armed robberies.

While studying journalism at the University of Michigan in the early 1950s, James Minder, now in his late seventies, used a sawn-off shotgun to hold up banks, drug stores and jewellery stores in the Detroit area.

He went on to serve additional time for trying to escape from prison. Under American gun laws, convicted felons who serve more than a year in prison are banned from owning or handling guns for life.

The 150-year-old gun manufacturer, which was founded by Horace Smith and Daniel Wesson in 1852, rose to riches during the gun-making boom of the American Civil War. Smith & Wesson’s .38-calibre revolver, its nine-millimetre pistol and its .357 revolver have gained a reputation for reliability ? and regularly feature in lists of the top-ten guns used in crimes.

Minder claimed that he had always been open about his background, but had not mentioned his nefarious past to boardroom colleagues because “nobody asked”.

The gun maker’s code of conduct requires full, fair accurate and timely disclosure of information. On his release from prison, Minder graduated with a masters degree in social work. Later he set up a charity to offer psychological counselling to disturbed youths.

The company, while recognising his earlier mistakes, believes that Minder has led an exemplary life for more than 35 years and that he has made a huge contribution to the community.

He still sits on the gun maker’s board.

Brought down by a fluttering heart and a curious mind

He was the man to reunite a deeply divided board, ripped apart by a disastrous bet on Russian bonds. A former Intelligence officer in the US Marines, Mike ’Neill stood head and shoulders above other candidates vying to become the next ?7 million-a-year chief executive of Barclays Bank. By April 1999, shareholders were lining up to meet the commando who would take Barclays by storm.

Yet in a heartbeat ? an irregular one, as Barclays’ Harley Street specialist was to confirm ? their hopes were crushed. After a nasty bout of flu, ’Neill had been left with a heart murmur that his doctors advised could only be compounded at the helm of the high street bank.

’Neill lasted just one day. Later he found a job as chairman and chief executive of the Bank of Hawaii, a position that he held without incident for three years until he retired in August 2004.

Mindful of the rogue trading losses and tax evasion charges that were plaguing an arch rival, the Bank of Ireland board decided to break with tradition and appoint a chief executive from outside its ranks. In Mike Soden, the directors were delighted to find a man with a robust set of personal principles and duly instructed headhunters to lure him from National Australia Bank.

In May 2004, just a year after officially taking up the helm, Soden was caught with his browsers down when staff at the bank's recently outsourced IT department discovered that he had been surfing Internet porn sites on his company computer. Soden, who personally signed off the bank's policy on Internet use, admitted that he had accessed a site for a Las Vegas escort agency before a business trip there and resigned, saying that it was a case of curiosity killing the cat.

PR chief defeated by own goals

Alison Ryan’s beautiful relationship with the beautiful game was cut short in its prime when Sir Alex Ferguson, manager of Manchester United, learnt that his new PR chief had told a series of lies about her career. Ryan scored a hat-trick of own goals, including, allegedly, falsely claiming a first-class honours degree from Cambridge, forging a reference in the name of a lecturer at Manchester Metropolitan University who did not exist and claiming to have advised Tony Blair ahead of his election in 1997. The club withdrew the position before Ryan was due to start.

Washed away by storm of protest

Scarcely had the ink dried on Sir Ian Prosser’s contract to take the chair at J. Sainsbury in February 2004, when a storm of shareholder protest forced his new employer to change its mind. Sir Ian withdrew his candidacy swiftly ? a valuable lesson learnt two years earlier when he had bowed out of the running to head Standard Chartered amid much protest.

Jilted at the altar, the cruellest blow

The debacle at J Sainsbury was a double whammy for Whitehead Mann, the headhunting firm. Hired to appease mounting disquiet at John Ritblat’s apparent reluctance to split the roles of chairman and chief executive at British Land, the firm duly suggested Philip Yea as a possible chief executive. Negotiations progressed well and British Land was poised to announce proudly its new appointment, when Yea jilted them at the last moment. It emerged that he had also secretly been talking to 3i, which he joined a day later on a package of ?1.9 million.

Gambler who found fame and fortune

Never good with numbers ? he failed his final maths exam at school ? Nick Leeson bet one of the City’s oldest banks on the volatile Singapore futures markets, and lost.

Yet Leeson is an example to those who face new career challenges: an after-dinner speaker and commercial director of Galway United FC, he now earns more than ?2 million a year.