It stands alongside Shorts Brothers and Harland & Wolff as one of Northern Ireland's great industrial powerhouses.
Its company headquarters on the outskirts of Belfast city centre, while not as eye-catching or world renowned as Samson and Goliath, is a landmark for thousands of commuters who drive up and down the M2 each day.
Now the story of animal feed firm John Thompson & Sons, based on the York Road in Belfast, has been recorded in a book.
Named 'Gentle Giant' after the famous white horse of the company logo, author Mike Faulkner says the term can equally be applied to the firm as a whole – a global brand, yet quiet and unassuming.
Thompson's factory on the York Road is the largest multi-species feed mill in Europe and the firm has driven innovation in the animal feed industry over many decades, but the story began back in 1870 on a farm in a townland outside Ahoghill.
Mr Faulkner said the book came about after a box of photos collected by a former employee was discovered in a cupboard at the factory. Accountant David Best had been putting aside documents and photos with a view to building a company history or archive, or even setting aside a dedicated room at the factory, but the idea had fallen by the wayside after he retired in 2009.
When the box of files was re-discovered Thompson contacted Blackstaff Press, who recommended Mike take up the challenge of researching the company history.
Mr Best returned to the factory to help out and helped Mike contact many current and former employees and collate around 120 hours of audio footage to accompany the pictures.
Having remembered Thompson's white horse logo from his rural Co Down childhood, Mr Faulkner was astonished to find that the company was much older than originally thought.
"I had to fill in some large blanks and realised that the company was founded in 1870," he said. "With the help of Robin Thompson, one of the last family members to work at the firm before it passed out of family ownership, we discovered that the founder, John Thompson, came from a place called Heaneystown near Ahoghill, and the family ran a grocery store from the farm.
"He left the farm at aged 20 and opened the first mill in Belfast off the Shankill Road in 1870 and the family farm was demolished in 1995.
"During our research we learned that a neighbour of the family in Ahoghill used to have a shaft-driven mill and I imagine the young John looking at this horse walking round and round all day, and thinking that there must be a better way of doing things."
And do it better, John did.
The company moved to bigger premises in Donegall Quay in 1905 and incorporated in 1906.
John Thompson and his three sons – Joseph, William and James – worked in the mill all their lives, but it was the youngest, affectionately known as 'Mr James' by the workforce, who was most involved and had a passion for animal nutrition.
But even back in the 1920s, the company was innovating. Thompsons was the first to have a dedicated in-mill laboratory for testing finished products and analysing incoming raw materials, and became one of the first two-compounding mills in Europe.
The factory was also the first in Ireland to install cubing and pelletising machines in 1911.
Thomsons was the first animal feed farm in the UK to open an experimental farm in 1930.
It was at Downshire Farm where, in April 1941, James stood and watched the skies above Belfast blaze red with fire from the bombs dropped by German aircraft, assuming that the neighbouring shipyard or waterworks had been hit hardest.
Using just enough rationed petrol, he reached the feed mill the next morning to find it destroyed.
Mr Faulkner said his immediate reaction to the disaster was indicative of the spirit of the man and the company.
"Standing in the middle of the devastation, the yardman, Gorman, said, 'Mr James, what are we going to do?' and James replied 'Gorman, get this yard tidied up'.
"Belfast suffered more that night than any other city outside of London, but James Thompson set about rebuilding from day one. It took from 1942 to 1944 to rebuild completely and the mill was back in full production by 1945, which was extraordinary. Closing down was never an option."
'Mr James' is remembered with extreme fondness by his workers.
The longest serving Thompsons employee is Sinclair Brown, who started in 1944, shortly after the Blitz and witnessed the latter stages of the rebuilding operation. He went straight from school to the company and ended his 50 years employment with the company as a sales manager, witnessing many industrial changes.
Mr Faulkner said that one story which did not make the book involved an accident Mr Brown suffered at work.
"He was around 14-15, so it was his first few months of employment, and some boys were kicking a ball around in the mill yard, he was in goal, between two walls.
"He went to make a save and ended up going through a window in the building behind him and was so badly cut he nearly lost an ear. He was called to the managing director's office still in his bandages and James Thompson said he heard that there had been damage done to a window.
"Sinclair said, 'There was, Mr James'. James Thompson said that he never wanted such an incident again, and then asked: "By the way, who scored?" – this to me is the image of the paternalistic family-run company.
"Another employee I spoke to was Andy McClurg, known in Northern Ireland as 'Mr Mill' – he also started at 15 as a 'bag boy' and went on to become production director.
He said that the company always remembered that the farmer was (the) customer, they were in it for the farmer, and the farmer had to benefit."
While James and William concentrated on running the factory, John's oldest son, Joseph, was the creative one in the family – artistic and musical and a natural fit for the marketing side of business. It was he who commissioned English illustrator John Hassall to produce the famous company logo in the early 1930s.
"That big white horse, with a wee child on board in a cloth cap, chewing a straw, to me epitomises everything about the company, country roots, power, forging ahead," said Mr Faulkner.
The company did indeed forge ahead, but after James' death in 1962 – he had still been coming in to work daily up until about a week before he passed away – the company was eventually sold just two weeks later, with his son Melville in ill health and the Labour government about to introduce Capital Gains Tax.
The new owners were W&R Barnett, a well known grain merchant with close ties to Thompsons, and millers R&H Hall and Isaac Andrews in equal shares.
But with amalgamation, acquisition of many smaller family-run milling firms and absorption, the company grew steadily and now produces almost one million tonnes of feed every year.
"The story goes that the Donegall Quay mill was bursting at the seams. Another company, BOCM, was losing volume and was either going to have to leave Northern Ireland or acquire extra tonnage, and approached William Barnett's son Robert, by the mid-1980s, the managing director of Thompsons," said Mr Faulkner.
"He turned around and said, why don't we buy BOCM. The move was made and that was major step in terms of the increase in volume and the firm eventually became the biggest multi-feed mill in Europe, purchasing James Clow back in 2002."
But Mr Faulkner said with a strong culture of loyalty, the company is still very easy to deal with.
"In researching and writing the book, I didn't feel like I was dealing with a corporate client," he said. "When you put Thompsons in the context of Northern Ireland's industrial heritage, you see what an important part Thompsons and feed milling has played.
"In the early 1900s, there were the four big drivers, ships, ropes, linen and agriculture.
"It's a tremendous success story which should be shouted from the rooftops, but like a lot of family firms, Thompsons has a culture of modesty, it doesn't tend to blow its own trumpet, it tends to get on with business and maybe that's why it is going from strength."
Current Thompson chief executive Declan Billington said the company has no plans to slow down any time soon.
"The company, like many others, has faced a bumpy ride due to high grain prices and we had to put down millions of pounds just to continue normal business," he said.
"Northern Ireland is small enough and innovative enough, our agriculture companies are all in it for the same reason, we do have a tendency to work together for the benefit of the industry and the customer and most of us have been able to weather the storm.
"We have come through a difficult period and we do wish to grow and expand and while we are firmly embedded in York Road and are a big part of the community there, we will probably look at developing other sites, satellite locations are definitely part of the long-term plan."