An obsessive, secretive and often tyrannical boss, Forrest Mars, who has died aged 95, built a family-run corporation with an estimated $18 billion turnover.
Today Mars ranks with Hershey, Nestle and Cadbury-Schweppes as one of the main makers of chocolate bars and sweets. Although people are surprised there was a Mr Mars, his name has achieved immortality, at least on this side of the Atlantic, through his creation, the Mars Bar.
The bar, in fact, was created in Slough, Britain in 1933, to suit a sweeter tooth than the US one. It was introduced here the same year. Last year almost 50 million Mars Bars were sold in the Republic.
M&Ms, the bean-shaped chocolates which were not introduced to the Republic until 1986, is the brand most readily identifiable with the Mars corporation in the US. Milky Way, Snickers, Uncle Ben's rice and Pedigree petfood, the other products which make up the bulk of the private company's portfolio, are also household names on both sides of the Atlantic.
Forrest Mars was born in Tacoma, Washington in 1904, the only son of Ethel M. and Frank C. Mars. He was to follow his father into the confectionery business.
His parents divorced when he was young and he might have been a mining engineer, had it not been for the intervention of his father, who after a 15-year absence, bailed him out of jail in Chicago after seeing his name in a newspaper.
On vacation from his mining course at the University of California, Forrest Mars had got carried away on a Camel cigarettes advertising campaign and was arrested when he illegally postered dozens of sites around Chicago.
Shortly afterwards he began work with his father who had already developed the Milky Way, based on a chocolate malt drink.
In 1932, after he fell out with his father, he travelled to Europe and worked for Nestle in Switzerland, before launching the Mars Bar in Britain.
In 1964 he merged his company, Food Manufacturers, with his father's Mars Inc. In his lifetime he saw the Mars Bar transformed from a pre-war, handmade piece of chocolate, based on the Milky Way, to a mass-produced product which to an older generation will always help you "to work, rest and play".
The slogan, a registered trademark, is still carried on the side of the distinctive black and red wrapping and is a marketing triumph which has its origins in the austere climate of 1930s Britain where the eating of sweets was frowned upon.
Its marketing as a "nutritional food" was, of course, helped by a series of advertisements featuring piton-hanging mountaineers or drifting yachtsmen who always fell back on reserves of Mars Bars, while waiting to be rescued. The company's clever marketing record, which has made many of its products brand leaders, was famously tarnished by Forrest Mars turning down Universal Studios who offered a deal to put M&Ms in the blockbuster film, ET.
Instead, the extra-terrestrial alien followed a trail of Hersheymade sweets. Mars's obsessiveness was most apparent in his attention to the state-of-the-art production methods he brought to his factories.
But it also extended to punctuality and all his employees, who were known as "associates", had to clock in to their austere workplaces. He had a capacity to humiliate them and his three children who were raised frugally, even though Fortune magazine declared the Mars family to be the richest one in America in 1988.
Forrest Mars would scream frequently at his two sons and once, infamously, ordered them to kneel and pray for the company with other employees. John and Forrest Jr inherited the company in 1973 under a trust arrangement, but the death of their father who maintained an interest in the business, has raised speculation about the future of Mars Inc.
Forrest Mars: born 1904, died July, 1999