It is a line from her life and not a poem by Edward Lear: Josephine Powell once rode a chestnut mare to the magnificent Minaret of Jam.

I have never met anyone else who has made that same journey. But then few details of Josephine Powell’s life have been anything less than extraordinary. She was adopted as “Mother of the Kalmuks” – the Western Mongolian tribe – for cutting red tape after the Second World War to ensure that a group of Kalmuk refugees were not returned to face Stalin’s wrath but resettled in New Jersey instead. Her first real research was into the hormonal cycle of pigs. The godmother she never met, the diva Dame Nellie Melba, sent her a pearl every year on her birthday – they got smaller and smaller, then stopped altogether. And she rode back from Jam, the famous Seljuk monument in western Afghanistan, in 1960 with Sila, her Belgian sheepdog, tucked in a saddlebag.

Her own monument is the extensive collection of photographs she took during the 1950s and 60s of the remains of Byzantium, of the art and peoples of Iran and Afghanistan, India and Pakistan. It is an archive sought after by the Fogg Library in Harvard and the British Museum.

Nearly thirty years ago Josephine Powell took a flat in Istanbul. Locked away there in her field notes, in tens of thousands of photographs and in her stunning collection of kilims, textiles and domestic artefacts is a unique record of the nomadic life of Turkey. The hope now is that all this will find a benefactor who can provide the permanent home it deserves.

“I photographed everything, got lost frequently and saw a lot of things,” she tells me, with a sudden intake of breath and a rumbling, self-conscious laugh that serves as warning to any interviewer who thinks he can write her a pithier epitaph than she can come up with herself.

Josephine Powell is unlike other people – and not simply because she’s been places they never will, or because that laconic drawl and the hand-rolled cigarette forever dangling from her lips make her an unusual cross between Gertrude Bell and Clint Eastwood. Partly it has to do with where she came from and where she’s ended up. Any bookmaker hovering over her crib in 1919 would have fixed the odds on her leading a life somewhere in Central Park West, supervising grand dinners for an Astor or two. Instead, her Istanbul kitchen, the first time I saw it, was full of boiling beakers of vegetables and bugs used in the manufacture of natural wool dyes. It had almost certainly never been used to boil an egg.

Josephine Powell set out to become a medical doctor at Cornell University, where she met that other Lear-esque character, Suzy the pig with the fluctuating hormones. She ended up as a social worker instead. In 1947 she left America on the SSErnie Pile to take up a job with the International Refugee Organization. She did not return for another forty years, and then never for more than the time it took to give a lecture and pack her bags again.

She was a self-imposed exile working with displaced persons – Poles in Tanganyika, Kalmuks in Germany. When the work was done, she settled on Rome. A trip to Lecce, in the heel of Italy, led her to photograph a Byzantine mosaic – a triptych of the Madonna and Child – and curiosity led her to correspond with the leading Byzantine and Islamic art historian David Talbot Rice.

He invited her to accompany him to the heart of Byzantium to photograph the mosaics in the Grand Palace of Constantinople. That was 1955.

The photos had to be developed outside Turkey and the question was what to do while she waited to see how they came out. At that time it was very difficult for foreigners to go to eastern Turkey, but that did not stop Josephine. She had applied for permission from the military in Ankara but heard nothing. She was in Gaziantep, and about to return home, when she discovered on her plate at breakfast an anonymous envelope. It contained a permit to travel east.

Friends warned her of the perils of travelling on her own, but she found only courtesy: “People treated me better than I had ever been treated.” Strangers went hours out of their way to show her the route. “They invited me into their houses, fed me, found me somewhere to sleep, never molested me. It was never dangerous to me. It never entered my head that it might be.”

She settled into a life more peripatetic than that of the nomads she was to study. She had one foot in Rome and the other in the Hotel de Kabul, where she took a dollar-a-night room by the decade. From Afghanistan she went on to photograph India and Pakistan, and was given a commission to collect implements of everyday life for the Land- en Volkenkunde ethnographic museum in Rotterdam. Ironically, the photographic output of these years was snapped up by Thames & Hudson for reproduction in thick, folio-sized volumes designed to grace the newly fashionable coffee tables of the world on which she had turned her back.

It was while researching one such book – the complement to a large volume on kilims – that Josephine Powell came to the conclusion that so much of what then passed for knowledge about the provenance and designs of flat-weave textiles was pseudo-science. She set out on her travels again, to consult the nomads themselves, or at least those who were still connected to a communal memory, and to find out what they knew about their own handicraft. She also managed to collect one or two – or three or four – pieces along the way.

I remember reading an account of someone who found himself on the plane next to Krishnamurti, the Indian anti-guru who walked away from an attempt to turn him into a new messiah. One of the things that impressed this traveller was that Krishnamurti had no money, in fact not much of anything at all, and that he managed to float around the globe relying not on his own resources but on the respect of others.

Josephine Powell, too, has a cultivated effortlessness. Despite the curlicue trajectory of an extraordinary career, she won’t actually admit to having intended to do anything. A respected scholar who belongs to no academy; a respected photographer who admits to no other talent than the ability to point and snap; a respected authority on nomadic textiles who is best at describing what is not yet known.

She would be the last to subscribe to weird and wonderful theories about the primordial origins of motifs and designs. She is even reluctant to attribute a date to much of her collection: “Just because they’ve got holes doesn’t mean they are old.”

There’s no point pressing her on her ambitions. “I just did it. The opportunities arose. Life just sort of oozed.” Even the photographs which were to win her an entrée into the salon of the legendary art critic and connoisseur Bernard Berenson were an accident. She saw a Leica in an army PX which she admired as “a beautiful object” rather than as a means to an end. Berenson was a little over ninety at the time. She was admitted for twenty minutes but stayed for hours. “He knew so much. He was such a little man. So fragile.” Josephine Powell is merely eighty-four and not exactly a giant herself.

How did she end up going East? “Europe was already photographed by people who knew what they were doing.” By that time she was using a Hasselblad. The parallel with Krishnamurti is hardly perfect. For a start, Josephine Powell clearly has an acquisitive streak. It’s not so much materialism as “material culturalism” that drives her on. There is nothing luxurious about her lifestyle, but she certainly has a lot of stuff. For a start, she is surrounded by wool in all its woven variety, along with the things you need to make wool and weave wool and look after the blessed sheep who produce the wool in the first place.

There are different things that drive collectors on. Some are after the thrill of the chase, or the outsmarting of fellow collectors. Josephine admits that there are things she sees that she just has to have. “It’s a want that doesn’t allow you any peace. You go to bed and you still want it. And then when you’ve got it, and missed however many meals to pay for it, you feel terrible.”

The devotion she inspires in others suggests she collects not out of greed but from some higher, selfless motive. You can see it in the eyes of her loyal following. “She has a way of hypnotising people into doing things they wouldn’t think of doing,” said Murad Megalli, himself a collector of kilims. Megalli’s employers, the bankers JP Morgan, sponsored the renovation of the kilims on display at the recent exhibition organised by the Turkish Historical Foundation, who under current arrangements will be the custodians of her collection.

Even then she managed to get forty kilims restored for the price of twenty. I went along to the exhibition while it was being set up. Josephine Powell was seated at a table, walking stick by her side. Around her was an army of volunteers – a chap from the Getty Museum, a few doctoral students, an Italian archaeologist, a few bankers, a few professors, an anthropologist working in Kirghizstan, a friend from Germany… “I don’t bully them,” she says innocently. But she understands what I am asking: “I never know where they come from or where they go.”

What also makes Josephine different from most collectors is that she is interested in context. So many kilims in collections have been looted from the mosques to which they were donated, in the same way that treasure-hunters rip out coins from the ground.

Friends say her love of kilims comes from a hatred of tufted carpets inspired by not being allowed onto her mother’s prize white-field Persian rug as a child. This pop-psychology explanation may well have the sort of dubious provenance that she has spent her career disputing. Part of the attraction of kilims over carpets is that they were woven by women for their own use, not for a market. The women who wove the kilims would have had a very different attitude to the fragments which were carefully restored and mounted for the recent exhibition. “When it got old, they could just throw it out and make another one.” All the kilims she bought, she said, were from dealers. She tried once to buy directly from a household, but the members were flummoxed and had no sense of the carpet’s monetary value.

On display at the exhibition of her own kilims are not just the rugs but the actual tents in which the weavers lived. Had there been space enough, I’m sure she would have lodged a camel in her spare room in the weeks before the opening. I remember the partridges running around her flat years ago while waiting to become the star turn at an ethnographic exhibition she was assembling in Istanbul’s Museum of Turkish and Islamic Art.

A space in the recent exhibition was set apart for kilims distinct from the rest: not bold, geometric patterns but stripes – broad striations of ochres and terracottas, turquoise and madder reds. “Look!” said a guest at the opening as she giggled over one of these kilims, sounding less like the eminent professor she is than a schoolchild who has just caught sight of the headmistress’s knickers. These kilims, the handiwork of northwestern Anatolia, were woven by the first nomads to abandon their migration. The dimensions, and possibly the designs, show an adaptation to town life. They would have been draped over a pile of bedlinen in a house, rather than over a camel’s back. But they are not in any obvious way riotously funny. “They look exactly like Malevich!” the professor exclaimed merrily – and I suppose there is a passing resemblance between the deceptive simplicity of the work of settled nomads and the Russian Suprematist painters. It is all a vindication of Josephine Powell’s conviction that the kilims she has collected and exhibited have integrity as works of art.

Also in evidence is Josephine Powell’s understanding of colour and design, the way different weavers could re-create a theme. Although she does not say so openly, she has a bone to pick with a modern Turkey that has converted nomads into settled people and bestowed on nomadic women a less purposeful, less dignified way of life. She understands the ritual of the caravan – with the oldest unmarried daughter leading the way, the kilims which covered the cauldrons on the camel’s back perceived from a distance as the colourful standards of a benign army on the march. She empathises with a way of life in which the women had the time to produce woven works of art. In so many ways she feels it was more sophisticated, and certainly more hygienic, than contemporary urban life. To put it less kindly, she is a relic of another century, the last of the great occidental travellers collecting the relics of a disappearing sort of life.

Another one of those ironies that surround her is that she never learned Turkish. Her attempts ended literally in tears – not her own but those of the person trying to teach her. Not gifted in languages, perhaps? She speaks French, Italian, German and passable Farsi.

Yet even as an orientalist she is unique. For a start, she was never interested in courtly art. Josephine saw a beauty in the by-products of an everyday life that was ignored or despised. And she asked questions. What were the objects for? How did they work? Why were they made? And she was not simply there to admire. Along with the chemist Harald Böhmer, she helped establish the Dobag Project – the first Turkish women’s co-operative – which makes carpets using authentic designs and natural dyes.

We live in an age of networking. But Josephine is a net-weaver, a nomad who has spun the threads of her very own world. This leaves her ill-equipped to undertake the fundraising activities that would ensure that her collection has its proper home and that her work is available to other scholars. She has entrusted that task to the Turkish Historical Foundation, which wants to place her work in a Centre for Research into the Cultural Heritage of Anatolia, but so far such an institution is still merely an idea. Why the centre has yet to find the right bequest remains a mystery, but it may well have something to do with settled folks’ lingering suspicion of the nomadic life.

And yet I suspect it will be built. How? Don’t ask Josephine Powell. It’s a bit like her life. Things just happen.