The brief notice hardly warranted a second glance. Prosaic to the point of dullness, it was befitting of a minor business transaction between two closely connected millers. Yet rarely can so modest an announcement have had such momentous and monumentally far-reaching consequences as that which appeared in the Norfolk Chronicle of May 7, 1814.

Carrying the address of 'Stoke Mills, near Norwich', it read: 'Jeremiah Colman having taken the stock and trade lately carried on by Mr Edward Ames, respectfully informs his customers and the public in general that he will continue the manufacturing of mustard, and he takes leave to assure those who may be pleased to favour him with their orders that they shall be supplied in such manner as cannot fail to secure their approbation.'

Even with the prodigious power of hindsight it is impossible to detect within that short statement any hint of what was to come, still less the electrifying pace and enormous change that would follow in its extraordinary wake.

But the truth of it is incontestable: that formal, self-serving notice marked the first stirrings of a fortune-making business empire and a commercial power-house that was instrumental in transforming an economically depressed city which had been all but bypassed by the industrial revolution.

Within a little more than 50 years, Colman's and the mustard-making enterprise originally established on the banks of the River Tas would become not merely synonymous with a revitalised Norwich but renowned around the world. It was a spectacular success story, shown in the spreading expanse of a vast factory s between railway and river, that was almost without parallel in the history of Norfolk. By the end of the century Colman's was a global brand with the prestige to match.

Far and away Norwich's largest manufacturer and biggest employer, with an army of 3,000 workers, the business would be listed among the top 100 companies in a nation at the zenith of its imperial power and influence.

It was a commercial triumph beyond the dreams of anything Jeremiah Colman could have imagined when he took over control of Stoke Holy Cross Mill 200 years ago. But what makes this epoch-making milestone worthy of celebration and recognition is not the success by itself, great though that was, but the manner in which it was achieved.

To my mind, the greatest and most significant accomplishment of successive generations of the Colman family, and one which set their grand enterprise apart, was their steadfast commitment to social welfare that went hand in hand with their business operation.

In an age when exploitation and the pursuit of mammon was the norm for many a Victorian tycoon, they bucked the trend to join an enviable and honourable tradition of enlightened entrepreneurs that included the Cadburys and the Rowntrees.

Under the stewardship, most notably, of the patriarchal Jeremiah James Colman, the great Carrow enclave, stretching from the heart of riverside Norwich into neighbouring Trowse, became a veritable model of industrial benevolence that was the envy of many a blighted and downtrodden workforce across the nation. He was following in a family tradition, extending and improving upon the good pioneered by his pious and punctilious namesake.

His great uncle, known as Old Jeremiah, was a virtuous man of unbending principles founded in a bedrock of nonconformist religion. A prominent member of St Mary's Baptist Church in Norwich at the time he took over the water-mill at Stoke in the spring of 1814, he rarely missed a Sunday service, travelling the five miles there and back in a gig.

Noted for his 'sterling integrity… great kindness of heart and large heartedness in consideration for others', Jeremiah was nevertheless no pushover when it came to managing his business.

Living next to the mill, he had a reputation for standing by the mill gate with his watch in his hand, checking on late arrivals among his 30 or 40 workers.

Described as a 'homely man', Jeremiah was a thrifty, hard-grafter who abhorred extravagance and ostentation, yet understood the meaning of duty and loyalty. His commitment to improving the lot of his employees and their families was genuine and lifelong.

Even before embarking on his Stoke enterprise, he had helped establish a school in Norwich where the first guiding principle was that teaching reading and writing together with elements of arithmetic and 'especially the knowledge of the holy scriptures' were 'blessings of inestimable value to all classes of society, and which it is the duty of the rich to offer to the poor'.

Together with his nephew James, whom he adopted and later went into partnership with, Jeremiah added education to the fringe benefits of work at the mill. Among a host of initiatives introduced with the help of James' wife, Mary, was a school, at which boys employed in the mill were given half-day lessons in the firm's time and then expected to attend further classes in the evenings.

The social amenities that were to become a feature of Carrow life all had their roots in those early years at Stoke Holy Cross. As well as regular concerts and lectures, a special Christmas dinner and a Whitsuntide tea, there was a single class run by James and a clothing club administered by Mary, through which the firm added a bonus to sums paid in by workers.

It was in this atmosphere of 'hard work and piety, of interest in local affairs and the pursuit of the arts' that the youngster destined to take the family's social responsibility to a whole new level was brought up.

Jeremiah James Colman was in his early 20s when he succeeded to control of the firm following the deaths of his great uncle and father both within the space of three years.

It was left to him to oversee the business's move from Stoke and its extraordinary expansion onto a 26-acre site in Norwich that was well chosen to take advantage of cheap land, plentiful and advantageous rail and river communications.

From the windows of Carrow House, where he took up residence for the next 40 years, Jeremiah James surveyed a landscape transformed as mills, granaries, warehouses, factories and workshops sprouted by the Wensum.

Mustard-making was at the heart of the huge manufacturing operation with sales boosted by increasing affluence and astute marketing.

The bright yellow labels with the distinctive bull's head trade mark was introduced at Carrow in the 1850s and helped to make Colman's mustard one of the most instantly recognisable products in grocery stores across the country.

Jeremiah James' far-sightedness, however, extended far beyond the business of profit and loss. A man of puritanical convictions, disdainful of fuss or flattery, he inherited his parents' and great uncle's social conscience.

His views were summed up in a letter to his future wife, Caroline Cozens-Hardy, in which he observed: 'I hope we shan't lead an ideal selfish existence, for I am sure that it won't be a happy one if we do. Influence, position and wealth are not given for nothing, and we must try and use them as we would wish at the last we had done.'

According to his daughter and biographer, Helen Caroline Colman, 'he rejoiced in the opportunities of helping others'. For and for the greater part of his life the focus of that benevolence was his workforce for whom he initiated a range of benefits that were way ahead of their time.

Supported by his wife, a devout Methodist who was said to be the 'moving spirit' behind many of the pioneering welfare schemes introduced at the Carrow works, he built on the solid foundations of philanthropy practised at Stoke.

In an effort to encourage habits of thrift – he was a firm believer in the principle of 'waste not, want not' - Jeremiah James established provident funds, clothing funds and compulsory accident insurance and made sure every employee who was not insured against sickness through a friendly society joined a works scheme.

One of the first and greatest of his social experiments was the creation of a new school for the children of Carrow workers. The redoubtable Maria Cogman, who had been schoolmistress at Stoke, moved to Norwich and lessons began in 1857, within a year of work beginning on the first mustard mill.

Inviting his employees to take advantage of the educational opportunity, Jeremiah James wrote: 'Feeling that as employers we are bound to aid you in the education of your children, my Partners and myself will remunerate the teachers.'

From a single room in King Street, which the initial 22-strong roster of pupils, the school grew rapidly. Such was its success that by 1870 the number of children attending had risen to 324.

More innovations followed. In 1868, Caroline Colman launched a new works kitchen, offering workers cheap food and drink at cost price. Caroline ensured the kitchens, which were the forerunner of the staff and works canteens and later the Abbey dining room, were open at 5.45am to serve tea and coffee to those who had 'a long walk into work'.

Self-sufficiency, something of a watch-word for Jeremiah James, was further reflected in the creation in 1872 of a self-help medical club and dispensary that administered free health care for workers' wives and children in return for a penny a week. A 'sick visitor' provided similar attention to male workers and within six years Carrow boasted the country's first industrial nurse on the company payroll.

From the outset at Norwich, a deacon from St Mary's Baptist Church had worked as a part-time welfare officer and this was extended with an 'out-reach' mission into female workers' homes designed, in Caroline's words, 'to teach them to be better women and better wives as they grow up'.

Jeremiah James' moralising influence extended even further. A staunch nonconformist and keen supporter of the Salvation Army, the YMCA and the Pleasant Sunday Afternoon Movement which sought to offer 'improving activities' for working men on their one day off a week, he blamed drink for many contemporary ills and was successful in closing two-thirds of the pubs within a quarter-mile radius of Carrow by buying out the landlords. In their place, he opened a coffee house in Trowse.

At the same time he made available land for more than 200 allotments to workers within easy reach of the increasing number of houses he built for them in nearby Lakenham and Trowse.

Such sensibilities, together with his enthusiasm for promoting education and religious equality, were further evidenced in his launch of the EDP, as a Liberal newspaper for East Anglia, and in a political career that took him from the local council to the Palace of Westminster as the city's MP for almost a quarter of a century.

By the time of his death in 1898, the mustard magnate turned politician had changed the face of Norwich, turning it, in the words of one historian, from a 'somewhat corrupt borough with a declining woollen industry into a citadel of reform and a thriving manufacturing centre'.

In so doing, he had stayed true to his principles, by materially improving the lot of thousands of Carrow workers and enriching the lives of many more.

Characteristically, his will provided the small fortune of £2,000 for 20 years to be used to assist employees, ex-employees and their widows in need.

It was a fitting legacy matched by the company which established for the first time an old age pension scheme in memory of one of Norfolk's greatest and most generous-hearted of social reformers who eschewed an industrial revolution of 'dark satanic mills' in favour of an enlightened family tradition forged 200 years ago on the banks of the River Tas.

A display of Colman's merchandise is on show at the Museum of Norwich at the Bridewell, in Bridewell Alley, Norwich, which is open Tues-Sat, 10am-4.30pm. Visit www.museums.norfolk.gov.uk for more information.

The Colman's Mustard Shop and Museum is in the Royal Arcade, Norwich. Visit www.mustardshopnorwich.co.uk for more information.