Maryam Homayoun-Eisler pauses for a moment as she takes stock. In the same way that most people wouldn't have a clue as to precisely how many books they own, she struggles to number the works of art in her collection.
"Three hundred or so," she says, hazarding a guess.
To be fair her collection is scattered between homes in the US and the UK. And besides, she thinks she might be done with collecting. "Honestly, the personal collecting has taken a secondary role in my life," she says. "You only have so many walls." Her intention is to put her energies into art patronage, which will come as welcome news for two influential but relatively impoverished western institutions.
The British Museum and the Tate Modern - both swept up in and, to an extent, playing a central part in the positioning of Middle Eastern art as The Next Big Thing - have embarked on shopping sprees of contemporary work from the region. This, say observers, is momentous for the art and the artists. Choices made by these institutions can not only affect the status of living artists and the value of their work, but can also serve as a first draft of art history.
At the British Museum, an institution best known for its antiquities, the hunt is on for contemporary work that brings the story of Islamic art up to date; one of the jars series by the Iranian artist Farhad Moshiri, for instance, echoes the tradition of calligraphy. At the Tate, the world's most visited gallery of modern art, the priority is avant-garde output from the region - one recent purchase was Living Room, a six-minute video by Tehran-based Nazgol Ansarinia.
Unfortunately, this new-found fascination with contemporary Middle Eastern art has coincided with cuts in already meagre budgets. As a result, both institutions have become reliant for funding upon the generosity of a diaspora of wealthy art collectors from the Middle East, which raises an interesting question: exactly who will be writing that first draft of art history and, perhaps, shaping the direction being taken by contemporary artists from the region? The artists themselves, Western institutions or the personal tastes of a handful of individuals?
Middle Eastern art began to take centre stage in the spring of 2006, when Christie's, the international auction house, set up shop in Dubai. Its success inspired Bonhams to follow suit in 2008 and, that same year, Sotheby's opened an office in Doha. That autumn, the market-research group ArtTactic reported that the volume of modern and contemporary work from the region at auction had risen from about £1 million in 2006 to £17 million, and that average prices had increased by 260 per cent.
"We are trying to build a global collection and therefore the key sign for us is when art from a particular region becomes part of a more global dialogue, and that was what was happening with the Middle East," says Frances Morris, head of international art at the Tate.
The Tate bought its first work from the region, a collection of 55 photographic images by the Lebanese artist Akram Zaatari, at Art Dubai in 2008. At that point, says Morris, "we realised we couldn't become more active without the support of a group of helpers."
The solution was to form the Middle East North Africa Acquisitions Committee (Menaac). For a while, it had been a toss-up between the Middle East and South Asia, but in the end the Tate followed the money. One of the key factors that led it to that decision, says Morris, "was the availability and enthusiasm of individuals in London willing to support us".
From her perspective in Dubai, where she has worked in the arts for eight years, Antonia Carver, the British director of Art Dubai, saw a delicious historical irony at play.
"The story of the great western museums was how they plundered the East," she says. "What's interesting is the way that has flipped, so now we have people from those institutions that harbour Islamic treasures coming to the East to ask them to help fund what is happening in the West - and they in turn are happy to support these institutions. That's a fascinating power dynamic."
Fascinating and, for some, troubling. As the excitement mounted, The Art Newspaper sounded a cautionary note. Yes, contemporary art from the region was hot, wrote the paper's influential founder and editorial director Anna Somers Cocks in July 2009, but it was "still a fragile plant" that could "easily be trained in one direction or another by outsiders".
Curators and critics, auction houses and dealers, foundations and museums were "all in the game", she wrote. "It is still the western art institutions and western money, both pro bono and commercial, that give validation to contemporary art anywhere in the world."
The West had largely defined the avant-garde of Chinese art, the market's last big thing, "choosing for its museums and market the art that fitted its concept of what an avant-garde should be". Now, she feared institutions such as the Tate and the British Museum would similarly "colonialise" Middle Eastern art - especially the Tate, "because of the key role [it] has in the international art system. The decisive power of money will come down behind the Tate's choices, inevitably affecting what artists choose to produce."
This, believes Carver, remains "a really serious point" in a market that has seen prices rise steeply in two or three years.
In one respect, Somers Cocks's prediction was spot-on; it was just five months later that both the Tate and the British Museum announced they were setting up special acquisition committees to begin collecting contemporary Middle Eastern art. But what The Art Newspaper had reckoned without was the impact of a new breed of art "ambassadors" upon whom both institutions were to become utterly dependent for funding.
Homayoun-Eisler, who was 10 when her family left Iran in 1978, is one half of a dynamic London-based duo known in the trade as "The Two 'M's"; the other half is Maya Rasamny, who was six when her family left Lebanon in 1982. It is only a little fanciful to describe them as the Medicis of their time and place.
In the same way that the great Florentine family stoked the fires of the Renaissance, supporting artists such as Botticelli, Da Vinci and Michelangelo, so these wealthy expatriates, their collections bristling with work by the likes of Moshiri, Tanavoli and a host of younger artists, are fuelling the renaissance of Middle Eastern art.
Their influence is widespread. Both women have been involved with Art Dubai - Rasamny as a patron and a judge on the associated Abraaj Capital Art Prize, for which Homayoun-Eisler has acted as an artist nominator - and both are supporters of various initiatives, including Parasol Unit Foundation for Contemporary Art, the London-based educational charity.
Homayoun-Eisler is also an artist nominator for the 2011 Magic of Persia contemporary art prize, which aims to highlight the next generation of artists from Iran and the Persian diaspora, and in 2009 was one of the main sponsors of the Iran Inside Out exhibition at New York's Chelsea Art Museum.
They followed different routes to their current pre-eminence in the Middle Eastern art world. After studying political science at Wellesley College in the US and getting an MBA at Columbia University, Homayoun-Eisler worked first as a financial analyst with Credit Suisse First Boston and then in marketing with L'Oréal and Estée Lauder, before turning to art collecting. Rasamny might say she was only "a housewife who liked culture and wanted to learn more", but she was at least a housewife who put herself through a series of art courses at Christie's and Sotheby's.
Both women started collecting art in 2003. In 2009 they were invited by the Tate to become joint chairs of the Menaac group and by the British Museum to head a similar committee.
There is, of course, no escaping the fact that their central qualifications for the job are pots of money and access to a network of equally wealthy collectors. This was exactly the scenario that had been so energetically disparaged just a year earlier by Robert Hughes, the veteran art critic.
In The Mona Lisa Curse, a 2008 documentary for British television, Hughes launched a withering attack on the rising influence of such wealthy patrons. The spectacle of great public museums courting the rich was, he believed, a fundamentally unhealthy relationship forged by an unregulated art market in which soaring prices had squeezed out the museums, and which was good for nobody but the wealthy patrons.
It was, he said, "one thing for rich collectors to choose the art for their own galleries. But what happens when they start making choices for everyone else by bringing the influence of their own taste into the museum?"
The museums, of course, are adamant that this is not what is happening.
"I think it would be very worrying if individual private collectors were influencing the museum," says Morris at the Tate. "We have an institution full of curators who have enormous integrity and are extremely well-qualified to make good judgements.
"We are working with a group of collectors [who] support what we do and we love them for that; many of them have very good ideas… but we have a pretty good sense of where want to go and how we're going to do it."
"There is a vast difference between what I would buy for myself, and what I see being purchased," she says. "The Tate has gone so - how shall I say? - institutional in its choices that there is no way that anybody would want to live with these pieces at home; these are massive-scale or highly politicised works."
Porter says she is keenly aware that "for works to enter national museums is hugely important for that artist, so there's a big responsibility on us to make sure we are acquiring the right works". To that end the museum operates a system of "checks and balances", including another committee that scrutinises the appropriateness of selections.
Neither institution is blind to the possibility of a patron attempting to profit by pushing works on the museums by artists they already own. Morris plays down the ability of the Tate to move the market. "I think what really increases price is exposure across a number of different domains and the support of a powerful dealer network and the auction houses. We are part of that chain but I don't think we have a hugely significant impact on prices."
Nevertheless, "We are very, very conscious of conflicts of interest. We ask people to withhold a vote or even leave the room if they are interested parties in any way."
Homayoun-Eisler is convinced that the art market, though unregulated, is a "self-adjusting, intelligent market. What ends up having a high price frankly deserves it, and what doesn't, dies."
The focus of her own collection is art from Iran. Six of the 13 artists acquired since the group began work in 2009 have been Iranian - hardly surprising, given the dominance of artists from the country in the current boom. Besides, she says, "I am very interested in a very specific type of art by contemporary Iranian artists, nostalgic art that connects me to my own heritage."
One artist she does have in common with the British Museum is Farhad Moshiri. She has "five or six pieces" by him, including the 2008 painting Love Letter. The museum secured its only Moshiri before the group was set up, but the story of that purchase does illustrate the possible effect on an artist of being acquired by a major institution.
It would, perhaps, be too simplistic to credit Moshiri's adoption by the British Museum in 2005 as the tipping point in a career that hit a high at Bonhams in Dubai in March 2008, when his 2007 painting Eshgh (Love) became the first work by a Middle Eastern artist to sell at auction for more than $1 million. Nevertheless, in a stroke of luck (or genius) in 2005 the British Museum paid less than $2,000 for Drunken Lover, a painting of a traditional jar bearing lines in nasta'liq script by the 12th century Iranian poet Omar Khayyam, which had formed part of Moshiri's first solo show in London.
Since then Moshiri's jars have climbed inexorably in value. Each is different, of course, but the trend has been consistent: $82,900 for one at Christie's in Dubai in April 2009; $128,000 for another at Sotheby's in London in October 2010; and, six days later at Christie's in Dubai, another went for $422,500.
Such rewards are unlikely to persuade Homayoun-Eisler to part with her Moshiri or any other works of art. She says she has only sold three pieces since she started collecting, and then only because they didn't fit in. The new Medicis have a different agenda.
"For me and I think for Maya too, as long as the art of the region as a whole is platformed and purchased, which art it is frankly doesn't matter, as long as the culture is recognised," she says.
For Rasamny, working with the Tate and the British Museum has given her the opportunity to "be an ambassador for my culture".
She, too, is charmingly vague about the size of her collection ("I haven't sat and counted it"). She is, however, clear about its substance and purpose; it is "very much an East-West dialogue", in which Gilbert & George and Damien Hirst mingle with the likes of Shezad Dawood and Ghada Amer, and as such reflects her interests as a patron. For example, she and her husband Ramzy, the chief executive of the London-based investment firm Plurimi Capital, were among the sponsors of Miraculous Beginnings, a recent exhibition at the Whitechapel Gallery of the work of the Lebanese artist Walid Raad.
"I believe," she says, "that art is an international language and that it will cross and break down boundaries."
It is likely that the pair's influence on Middle Eastern art will only grow - and spread to the US. Homayoun-Eisler is also the executive editor of an ambitious series of heavyweight books published by Thames & Hudson that have focused on the contemporary art of Iran, Turkey and the Arab world. Both she and Rasamny, in fact, will miss Art Dubai this year because they will be in New York promoting the US launch of the fourth in the series, Art & Patronage - The Middle East, a book that shines a rare light into the collections of some of the region's wealthiest patrons.
"It is," says Homayoun-Eisler, "amazing that the British institutions have taken such a lead in this process. I very much hope that they influence American institutions, because in the US there has been very little focus on Middle Eastern Art, partly because the Middle East and Iran and so forth have always been taboo topics, especially since September 11."
For the future, she sees herself "serving a useful purpose in the areas of publications, curatorial support and purchases, and perhaps research ... I would love to be able to help one of these institutions set up the best possible library of Middle Eastern contemporary and modern art, because there is no such thing today available in the West."
The Tate already has its Daskalopoulos Curator - Jessica Morgan, appointed last September - whose job is paid for by the foundation of the Greek art collector Dimitris Daskalopoulos. Could we expect to see an Homayoun-Eisler Curator at the British Museum some day soon? "Yes," she says, "you possibly could."
Of course, Robert Hughes probably won't like this, but then he isn't faced with the prospect of maintaining the relevance of a major institution with an acquisitions budget barely sufficient to cover the walls with a few prints from Ikea. Porter says the official budget for her whole Middle East department is £8,000.
The bottom line, she says, is that "in this time of austerity… this kind of philanthropy is important and these wonderful people seem to really believe in what we are doing. When you get that kind of gift it's up to me, in my position as a curator, to make sure I use this money in the best possible way."
Jonathan Gornall is a features writer at The National.