Move over Coleen Rooney, this was the first Wag

She had a bias-cut, silk evening dress with diamante clasps on the belt and pink, satin-backed crepe shoulder drapes. There was a classic 1910 bathing suit, jewellery from the distinguished Boodle & Dunthorne and a fine Edwardian chemise.

Considered separately, these items might simply reflect the eccentricities of some long-dead fashionista. But, together with more than 1,000 other garments, hats, shoes and collectibles which have also just been put on public display, they constitute the largest single collection of one woman's clothes owned by any museum in Britain.

Furthermore, they show that almost a century before Liverpool's footballing Wags such as Coleen Rooney, below, gripped the public imagination, one woman had already discovered the joys of retail therapy. The pioneer in question was Emily Tinne, the wife of a prominent GP and exalted socialite in early 20th-century Liverpool.

Born Emily Margaret McCulloch in India in 1886, a decade after Queen Victoria named herself empress of the sub-continent, she was sent to boarding school in England at the age of seven by her Presbyterian father. After leaving school in 1904, she trained briefly as a domestic science teacher before moving with her aunt to Liverpool two years later. There she met a handsome bachelor with deep pockets.

Their romance blossomed 97 years after Jane Austen penned the opening lines to Pride And Prejudice, declaring it a "truth universally acknowledged that a single man in posession of a good fortune must be in want of a wife". And so it proved with Philip Tinne, an eligible young doctor with impeccable family credentials. The Tinne family had arrived in Liverpool from the Dutch colony of Demerara, now part of Guyana in South America, almost a century earlier. Their involvement in slavery, sugar and shipping helped them to accumulate a vast fortune. The future Dr Tinne had family money (which would pay for his sons to go to Eton) and an education too. On 14 July 1910, he and Emily wed in the heart of the city. With money to burn, she began to shop to her heart's content.

At first, it was mostly daywear – dark dresses, comfortable shoes, tit-bit adornments. In 1923, the couple moved to Clayton Lodge, a mansion on the affluent suburb of Aigburth. Here, Dr Tinne set up a GP surgery as an adjunct to the house, caring for the poor of Garston, a neighbouring working-class area. Meanwhile, Mrs Tinne's shopping sprees intensified, with regular visits to Bold Street ( known as the "Bond Street of the North") and tours of department stores whose names were a roll call of middle-class exuberance: George Henry Lee & Co Ltd (now part of the John Lewis Partnership), Bon Marché, Owen Owen and the legendary Cripps, Sons & Co.

Her wardrobe swelled in proportion to the economy and wealth of Liverpool in the inter-war years. In 1910, when the Tinnes first moved to the city, it was establishing itself as the engine of the British Empire, a colonial gateway pulsating with trade and industry. The First World War was a painful interlude but the Roaring Twenties brought wealth back to Liverpool with a vengeance. It was only when the Depression hit that Mrs Tinne's fortunes and those of her city were out of kilter.

And yet, as the exhibition at Liverpool's Sudley House – A Sweet Life: Fashion In A Liverpool Sugar Merchant's Family – shows, the curious thing about her collection is not just its size, it is the fact that half of the items were never worn – many of the pieces were still in their original boxes.

"I've thought long and hard about why that might be," said Pauline Rushton, the exhibition curator. "And it is important not to portray her as an airhead because she had a wonderful social conscience, organising pensions for widows, schemes for unmarried mothers and so on."

One theory is that, with seven children and as the wife of a busy GP, Mrs Tinne had limited time to socialise.

"The fact is that she just enjoyed shopping. You can tell she was addicted to it from the fact that she bought multiple copies of several dresses, each in the same size but of differing colours. Many of them still have their labels and price tags. Those are clear signs of a shopaholic."

Mrs Rushton believes it is impossible to put a price on the clothes in the exhibition, but Mrs Tinne's last surviving child, Alexine, now 86, thinks there may be other ways to measure its value. "She had had a pretty hard time at boarding school and when she got access to money she enjoyed buying nice things," she said. "When she died [in 1966] I cleared 52 tea chests full of dresses, shoes and hats from her attic. They were time capsules. You could open any one and think 'this is from a particular year'. It was like reaching out and touching history."

Ultimately, war prevailed and the advent of clothing rations put paid to Mrs Tinne's sartorial ambitions. "My mother was frustrated intellectually and in a different era she would have done different things," her daughter said. "A generation later, she would have probably had a career."

Somebody had better tell Coleen.

Carola Long: Fashion works its spell across the centuries

Emily Tinne's extensive wardrobe shows that while shopping may have changed radically over the past century, the psychology behind it has not.

Her wardrobe, and her daughter's insights into it, suggest that like today's aspirational consumers, she often shopped for the life she might have wanted rather than the one she actually lived. Pauline Rushton, who curated the collection, highlights "fantasy dresses with low backs and slender silhouettes fit for a Hollywood starlet". Similarly, a rabbit-fur trimmed evening coat of black silk velvet, bought at a local department store, was more suited to the red carpet than the modest social life of a doctor's wife.

Emily Tinne's daughter, Dr Alexine Tinne, doesn't think her mother wore many of the more glamorous pieces, partly because she didn't have the occasion to, and also because her husband would have deemed them too revealing. Women of her time were deemed middle-aged much earlier.

More suited to Tinne's lifestyle, although rather less glamorous, were the loose, drop-waisted dresses she wore every day. Her familiarity with high fashion is clear in shapes that echo the designs of Paul Poiret and a crepe dress with an Art Deco buckle.

Her daughter believes much of her extravagance was aimed at helping local shopgirls who worked on commission, but the flashes of glamour – and even bling – suggest that Emily Tinne was also firmly under fashion's spell.