Long before pound shops were growing on the high street, a Cornish entrepreneur was pioneering a new form of discount retailing.

Trago now boasts 38 departments covering categories as diverse as clothing, furniture, electricals, stationery, car care and gifts.

By his son’s own admission Mike Robertson’s early retailing undertakings can best be described as “under the radar” and there’s certainly a hint of Del Boy and Rodney about the birth of Trago Mills.

Now it is celebrating its 50th birthday and has become a south-west institution, not to mention a key local employer, with three stores and an annual turnover of more than £80m.

It could all have been so different had the original plans of Mike and his wife Pam not been scuppered by local authorities.

“Initially my parents wanted to develop a disused explosive factory site as a sportsmen’s resort that would offer some of the best freshwater fishing in the county – and be run in conjunction with their shark-fishing vessel,” says Trago Mills’ chairman Bruce Robertson, son of the late founder. “Regrettably, the authorities thought otherwise and the rest is history.”

Instead, the Robertsons combined their vision for what amounts to a theme park crossed with a shopping mall and Trago Mills was born.

The first store opened on the outskirts of Liskeard in 1965 and offered an eclectic range of general merchandise at discount prices. A further two stores followed in Newton Abbot in 1967 and Falmouth in 1976, and there are plans to open a fourth in Merthyr Tydfil in Wales.

What sets Trago apart from other independent retailers is the iconoclastic nature of the Robertson family. Throughout his business career Mike Robertson was resolutely anti-establishment. His battles with officialdom, particularly over planning permission, made him a celebrity in the West Country and his support for Eurosceptic political parties has been adopted by son Bruce who is a prominent Ukip donor.

“The main reason for our longevity is our total commitment to offering unbeatable prices on tens of thousands of products”

Bruce Robertson, Trago Mills

There has been no shortage of bumps along the road for Trago. In 2011, the retailer was found guilty of dumping several thousand tonnes of waste, including asbestos, at its Newton Abbot and Liskeard sites. It was also the subject of a sting by the TV show Fake Britain after it was found to be unknowingly selling fake branded shampoo containing a chemical used in sex change treatments. Yet the business consistently manages to absorb each shock and emerge with its popularity in tact.

The individualism and theatricality of the Robertsons is reflected in the Trago stores. Newton Abbot in particular, with its distinctive castle-like appearance, has become a destination for shoppers. The site spans 100 acres and incorporates restaurants, a garden park, a family fun park and a steam railway.

From clothing to car care

The product offer has also evolved over the years. Trago now boasts 38 departments covering categories as diverse as clothing, furniture, electricals, stationery, car care and gifts.

It also owns a motorcycle dealership, Trago2Wheels, and has a contract sales division. Price is still at the core of the Trago Mills proposition and the retailer promises to match its prices against all high street competitors within a 50-mile radius of Trago stores.

Expanding the business has not been without its challenges. Sales have hovered between the £80m to £90m mark for the past decade amid challenging trading conditions – including competition from the supermarkets and discounters – and the fallout from a fire that devastated the Newton Abbot site in 2004 and forced a partial closure until mid-2005.

But Bruce Robertson remains bullish about the retailer’s prospects as it enters its 50th year. “There’s no doubt the main reason for our longevity is our total commitment to offering unbeatable prices,” he says.

Trago plans to mark its milestone birthday with special promotions and activities across the year, including a ‘party’ event at its stores.

It has also recently launched a click-and-collect service.

Not bad for a business whose founder had his heart set on shark fishing.