It's the Oscars this Sunday, so the perfect time to brush up your Oscar gown IQ. Since the first Academy Awards ceremony in 1929, when Mary Pickford wore a daring bow at the chest, the Oscars has been all about statement, show-stopping gowns. Marlene Dietrich caused a stir in 1951 when she arrived in a dress to the knee and Robert Osborne's Official History of the Academy Awards reads: 'Thanks to Dietrich, the evening was blessed with showmanship.' It was Angelina right leg flash of the 50s.

Since 1929 there have been plenty of iconic Oscar gowns, from Gwyneth Paltrow's candy pink Ralph Lauren gown she wore when she picked up Best Actress gown in 1999 for Shakespeare in Love to Kate Hudson's 2003 Versace dress hand sewn with 14-carat gold. It was at the Oscars where Sharon Stone paired a lilac Vera Wang skirt with a super casual Gap buttoned shirt and where Hilary Swank braved a navy backless Guy Laroche gown.

Award presenters Audrey Hepburn and Grace Kelly backstage at the 28th Annual Academy Awards, 1956

You may remember Grace Kelly's mint green satin dress she wore in 1955, which cost $4,000 to make and was the most expensive dress in Oscar history at that time. Who could also forget the Givenchy belted dress Audrey Hepburn wore to the 1954 Academy Awards. Audrey didn't spend the whole day getting pampered like starlets do nowadays, as she had just finished filming before the ceremony and barely had time to change let alone fix her makeup. She was still wearing her heavy stage make up when she accepted her Oscar for Roman Holiday.

Fashion at the Oscars shifted up a gear, when the Academy appointed an official style consultant in the late 80s who instructed that 'Everyone should be elegant. Everyone should look like a movie star.' Before the 1979 Academy Awards the show's costume consultant Rob Talsky instructed the female nominees: 'No comfort, not what's in style, but glamour with a capital G.' Amen.

Skip to 2013, the Oscars is still all about glitz and glamour, but these days it is a much more complicated operation. Couturiers spend weeks creating gowns to fit perfectly and stars are plucked, preened and squeezed into couture to be paraded in front of the world's fashion police. It is a fierce, fierce battle between fashion houses, for example fifty designers competed to dress Julia Roberts at the 2001 ceremony. It is highly political, as Charlize Theron insisted on being the only star to wear Gucci on the red carpet and, of course, Gucci agreed.

Valentino and Anne Hathaway at the Oscars, 2011

Valentino said that dressing Julia Roberts when she collected her Oscar for Erin Brockovich was the highlight of his career. 'I have dressed so many people but I have to be sincere. The person that made me feel so very, very happy was Julia Roberts. When she got the Academy Award for Erin Brockovich I watched it on television and really I was so excited that she appeared in my dress,' the designer gushed.

The monochrome vintage dress from his 1982 collection may go down as one of the most iconic gowns of all time, but her niece Emma Roberts called it the 'skunk dress.' Charming. Valentino is a popular choice for Oscar winning actresses, as Best Actress winners Cate Blanchett, Sophia Loren, Jessica Lange and Elizabeth Taylor all wore Valentino.

Still need proof of how much work goes into one Oscar winning gown? Let's take Cate Blanchett's Oscar winning yellow Valentino number - it was made by ten seamstresses, took nearly three weeks of eight-hour days to make, used eleven yards of silk taffeta, and was delivered by 'the one person that Mr Valentino approved.' 

Ready to see the most iconic Oscar dresses of all time? See all the iconic frocks from Halle Berry's Elie Saab red and sheer bodice gown she wore in 2002 to Rooney Mara in white Givenchy at last year's ceremony in the gallery above. 

*It's official, we are about to explode with Oscars excitement. Bring on Sunday night!