A lot can happen in a year. The optimism of 2008 has given way to a seriousness not previously known to the women on this year's list. Too young to have learned from the last recession, they've found themselves in the business deep end without armbands. Which gives us even more reason to celebrate their exceptional success - if you can make it now, you can make it any time.
Check out MT's '35 Women Under 35 2009' feature as a PDF
Our 2009 line-up is notable for a number of reasons. Although the average age remains the same as last year - just 31 - we feature the youngest-ever to appear on the list. Inventor Ruth Amos is 19, and is taking three years out after her A-levels to build her StairSteady business. 'My age is not only my biggest help but my biggest hindrance,' she says with a confidence that belies her youth. 'When I started off, every major bank refused me business banking, and that was something that hit me really hard.'
Close to two-thirds of our high-achievers studied what some still think of as 'male' subjects at university: science, business, law and economics; a third went to Oxford, Cambridge or the LSE. Over 50% of the women on this year's list work in traditionally male sectors, and our '35 Women Under 35' poster girl must surely be Katy Taylor. The 28-year-old has a first-class degree in geological sciences from Cambridge University, a Masters degree in engineering from Dartmouth College in the US; she started her career as an officer in the British Army, joined management consultacy McKinsey, and is now head of business planning at the Metropolitan Police.
Jade Tong works in the macho world of commercial property. She is an associate director at commercial real estate business DTZ. Being one of few women in the sector, she says it's 'about being yourself, bringing something different to the mix. I don't worry about the advantages or disadvantages of being a woman. I just enjoy it and learn from the experience.'
But our 2009 heroines have succeeded in every kind of business. We have representatives from advertising, management consultancy, cosmetics, the law, banking, retail, engineering, property, PR, IT, broadcasting, the arts and the public sector. Take Savannah Miller, who runs fashion label Twenty8Twelve with movie-star sister Sienna. What's the secret to her success? 'Just a fierce determination not to give up. If you want something bad enough, you can get it - no matter what.'
With two young children and a teenage stepson, Miller has her work cut out. 'As a woman, it's extremely challenging juggling all that stuff, but I wouldn't have it any other way. Having a family gives me a determination to succeed.'
When a capacity for ferocious hard work allies itself with green campaigning, the result is cover star Kate Hampton. She has just been made director of climate-change policy at the Children's Investment Fund Foundation, before which she worked at Climate Change Capital and Friends of the Earth. She was also named World Economic Forum Young Global Leader in 2008.
Again, being female and under 50 made her stick out from her grey-haired male policy-wonk peers. 'In my twenties, the real problem was getting people to take me seriously - especially older men. And I think the key to everything is to maintain your confidence.'
The cut-off age for the women on the list is not accidental. Thirty-five is a landmark birthday: a time when, for many, career lift-off coincides with having children. This year is a first for MT in that four of the women on the list are on maternity leave. We're unafraid to raise an issue that's often swept under the carpet. According to the Equality and Human Rights Commission, an estimated 30,000 women every year illegally lose their jobs as a result of pregnancy, and that figure is expected to rise during the recession.
Happily, Samantha Mangwana - another MT cover star - who is a solicitor with employment firm Russell Jones & Walker, specialises in cases of discrimination litigation for individuals, particularly sex discrimination in the City. 'It's an unfortunate reality,' she says, 'that in many different industries, women on maternity leave are the first to be contemplated for redundancy at a time in their lives when they and the future that they're bringing with them could not be more vulnerable.'
At a time when talent has never been so valuable, business needs to support women, not hang them out to dry.
SAVANNAH MILLER, 30
Creative director of designer label Twenty8Twelve, Miller has hit the fashion spot. The Central St Martins' graduate previously worked for Anya Hindmarch, Betty Jackson, Matthew Williamson and Alexander McQueen. Miller set up the business with her sister Sienna in 2006. It put on its first catwalk show this year.
KATE HAMPTON, 34
An LSE graduate with a masters from Harvard, Hampton began her career at Friends of the Earth, as head of its climate-change campaign. She then moved to Climate Change Capital as head of policy, before joining the Children's Investment Fund Foundation this year as a director. She was named a 2008 World Economic Forum Young Global Leader.
SAMANTHA MANGWANA, 34
An employment solicitor at Russell Jones & Walker, Mangwana specialises in discrimination law. She has worked on high-profile cases, including acting for BNP Paribas trader Katharina Tofeji in a test case. She is a trustee of the Fawcett Society, the leading national charity campaigning for gender equality.
RUTH AMOS, 19
The youngest-ever woman on our list, inventor Amos turned her GCSE coursework project - StairSteady, a device to help people to climb stairs - into a business in 2007. She won the 2006 Young Engineer for Britain award and is now taking three years out to build her business before starting university.
JADE TONG, 34
An associate director at DTZ - the fourth-largest global real estate adviser - Tong is one of few women at her level in property. She has won more than £23m worth of business for the company, including the Crown Prosecution Service, the Home Office, Pfizer and Johnson & Johnson. In 2008, she secured lottery funding to help set up a Vietnamese and Chinese community club for the elderly.
LAURA STEVENSON, 32
Joining Sadler's Wells this year as general manager, Stevenson is responsible with the CEO for setting the strategy of the London dance theatre company. The Cambridge graduate and ex-McKinseyite was previously deputy director at the Hayward Gallery and general manager of the Tate's collection division.
RACHEL BARTON, 33
As a senior executive in Accenture's CRM practice, Barton has an impressive track record, handling multi-million-dollar deals, and was recently voted most inspirational leader for management consulting in Accenture's people Oscars. A UCL graduate in physiology, she has worked at the Institute of Neurology.
ALEXANDRA BASIROV, 32
Joining BNP Paribas in 2006, Australian-born Basirov heads its sovereign, supranational and agency debt capital markets team in the UK. The LSE graduate's star should stay in the ascendant as demand for bank bail-outs continues to drive governments to the capital markets.
LISA BURGER, 35
Starting as a YTS trainee at Monarch Airlines, Burger joined start-up easyJet, where she went from the check-in desk to leading the entire airport operation, handling a budget of £350m. As director of operations, Starbucks central London, she is now responsible for £50m in sales and 1,000 employees.
KATE CRAIG-WOOD, 32
Craig-Wood began her career at Arthur Andersen. She co-founded web and IT hosting provider Memset with brother Nick in 2002 - it now turns over £2m. In 2008, transsexual Craig-Wood won a NatWest Everywoman award. She was the first woman to tandem skydive onto Everest.
EMILY CUMMINS, 22
Her love of inventing began at the age of four, and Cummins' latest creation - a solar-powered fridge - is helping thousands of Africans. She won 2007 British Female Innovator of the Year and is now studying management and sustainability at Leeds University, where she was its Enterprise Scholar 2008.
OLLY DONNELLY, 29
An Oxford geography graduate with stints at Accenture and the World Bank, Donnelly founded Shivia Microfinance last year, a charity that works with the poorest in Nepal and India. She is also MD of Leadership Media Advisory and director of Do Development, which advises corporates on CSR.
ZEENA FAROOK, 27
A geotechnical engineer at Arup, Farook was named New Civil Engineer's graduate of the year in 2006. The Oxford scholar has continued to shine, working on Arup's Olympic Park infrastructure group in London, the Rees Way Mosque in Bradford and on projects for Leeds Metropolitan University.
ELSPETH FINCH, 33
A transport planner by background, Finch co-founded pedestrian modelling consultancy Intelligent Space in 2000 at the age of 24. The firm was bought by Atkins - the UK's largest engineering consultancy, with a £1.3bn turnover - in 2007. She is now director for highways and transportation at the group.
MELISSA GEIGER, 32
The youngest of 565 equity partners at KPMG, Geiger works within financial services tax, and leads the financial M&A team in London. She previously worked at Accenture and Standard Chartered, where, as a rising star, she was selected to be UK CEO for the day. She's an accomplished ballroom dancer.
SOPHIE HOWARTH, 33
Before becoming founding director of the School of Life in 2008 - a philosophy school and shop, whose teachers include Alain de Botton and Martin Parr - Howarth worked as head of education at Iniva and was curator of public programmes at Tate Modern. She writes about photography.
JOHANNA KYRKLUND, 32
A Financial News Rising Star, Kyrklund is head of world multi-asset business at Schroders, responsible for investments of £11.2bn, and a member of its five-person global asset allocation committee. The Oxford graduate was previously at Deutsche Asset Management and Insight Investment.
PRIYA LAKHANI, 28
Ex-barrister Lakhani quit in 2008 to start Masala Masala, an authentic Indian sauce company, and was soon voted Daily Mail Enterprising Young Brit. Her sauces are sold by Waitrose, Harrods and Harvey Nichols. She set up the Masala Masala Project - for every pot sold, a homeless person in India is fed a meal.
CLARE LANGFORD, 28
Tesco's category technical manager for salad and prepared produce manages a turnover of more than £18m a week. Langford leads a team that sources product from more than 2,000 growers across 20 countries. She has been identified by Tesco as one of its future leaders.
CLAIRE MASON, 34
The Oxford graduate set up PR agency Man Bites Dog four years ago and has won several awards since, including PR Week's New Consultancy of the Year 2007/8. A specialist company targeting professional services firms, the agency boasts profit margins four times the industry average and is expanding fast.
SOPHIE MAUNDER-ALLAN, 35
At 29, Maunder-Allan became the first female shareholder at VCCP - the ad agency behind the comparethemarket.com Meerkat campaign - and then the first female equity partner. Now head of strategic planning, she has won the IPA Effectiveness Awards Grand Prix and a Gold for client 02.
LISA MYERS, 31
Norwegian-born Myers is an expert in search marketing and search-engine optimisation, founding consultancy Verve Search in February this year. She was head of search at Base One, during which time she won the award for the under-30 category of the BlackBerry Women & Technology Awards in 2008.
ROSIE NAGRA, 32
Joining Reckitt Benckiser in 2007 as marketing manager on Finish, its flagship global dishwashing brand, Nagra had previously worked at Kraft Foods for six years, where she helped launch Philadelphia Splendips. She was one of Marketing Week's 2007 Top 50 Rising Stars.
AZITA QADRI, 35
Cambridge graduate Qadri is the woman behind Eat Your Cake, which helps start-ups recruit high-calibre professionals who need flexible working hours. Qadri brings her experience from eBay, where she got retailers to sell excess stock on site, and from her Insead MBA. She plans to take Eat Your Cake Europe-wide in 2010.
DEBORAH REGAL, 34
During her 10-year City career in foreign exchange sales, Regal worked at Bloomberg and JP Morgan. Now studying at the Bar, she is also an independent member of the Metropolitan Police Authority and was named Pro Bono Hero by the Attorney General in 2008 for her legal charity work in various sectors.
CLARE REICHENBACH, 35
As BBC Worldwide's head of strategy, Reichenbach is responsible for supporting the CEO and directors in the corporate strategy of the BBC's commercial arm (turnover: £1bn). The Oxford graduate, who also worked for Gemini and BSkyB, was head of strategy for BBC Vision.
EMILY SHENTON, 33
Shenton joined Unilever as a graduate trainee but moved to start-up media company eDv, taking it to a multi-million-pound turnover. She left business to pursue a career in CSR, in 2004 joining as MD Arrival Education, a charity that links inner-city schools with businesses to give pupils career support.
KATE SMAJE, 30
Smaje is the youngest partner globally at McKinsey & Co, where she specialises in retail. She began her career in M&A at Chase Manhattan and JP Morgan, before rising through the ranks at McKinsey to be elected partner last year at 29. She is involved with Arch, a charity for children in developing countries.
EMER STAMP, 34
Senior creative director at start-up ad agency Adam & Eve, Stamp was responsible for winning the John Lewis account and for the Daily Telegraph's 'It pays to think big' campaign. She joined from DDB in 2008, where she won the IPA Grand Prix. Campaign has identified her as an executive creative director of the future.
GAYLE TAIT, 32
After graduating from Oxford, Tait joined L'Oreal's graduate scheme in 1999, eventually working her way up from marketing director for L'Oreal Paris UK to general manager for L'Oreal Paris UK and Ireland, with a team of 90. Tait has produced revenues 30% ahead of the market for the past three years.
KATY TAYLOR, 28
The head of business planning in the Metropolitan Police's strategy department began her career at McKinsey, where the Cambridge graduate co-founded a sports consultancy and worked on the commercial strategy for the London 2012 Olympics. Before that, Taylor served as an officer in the Army.
BIJAL THAKORE, 27
Previously client development officer at Lego, the aerospace engineer now runs her own engineering and business consultancy, Big On Good. She also worked at Airbus and Rolls-Royce, and was awarded the 2009 Women Engineering Society's Young Engineer Award. She is on the board of The Planetary Society.
HOLLY TUCKER, 32
Co-founder of notonthehighstreet.com, Tucker and business partner Sophie Cornish have been selling luxury wares from small businesses across the UK since 2006. The business is on track to turn over £6m this year. Before setting up the e-tailer, Tucker was in sales at Publicis and Conde Nast.
BIANCA WATTS, 31
Watts is already making big waves as an executive director at Morgan Stanley Private Wealth Management, where she heads a team advising the super-rich across Europe and the Middle East. Watts joined as a graduate in 1999 and soared through the ranks - she was one of Wealth Bulletin's top five rising stars 2007.
NEMONE WYNN-EVANS, 34
The CFO of junior London stock exchange Plus Markets Group is a former Oxford rower, whose mother was among the first women to be a member of the Stock Exchange. Wynn-Evans left the LSE in 2004 to join Plus Markets, having previously worked at KPMG and HSBC James Capel.