Some styles are just too good to be forgotten, even in the noughties.

1. Bobbing along
The bob has been a classic since the original A-lister, Queen Cleopatra.

Defining moments:
'20s - Silent screen actress Louise Brooks had only a brief career, but her precision haircut made her an iconic poster babe for decades. '60s - Updated 'flapper' cuts became wunderkind crimper Vidal Sassoon's stock in trade. His client Mary Quant was a key mover and shaker in Swinging London. '80s - Power bobs were geometric and hard-looking and seemed to send the signal 'take me seriously' rather than 'run your fingers through my hair'. '00s - Amber Valletta's blonde interpretation is no less stunning, but the shape is softer and less defined in the spirit of low-key glamour. The mantra for the noughties is natural.

2. Sweet urchin
The cute, cropped haircut has a long history.

Defining moments:
'50s - Audrey Hepburn was like a beautiful gazelle with her micro fringe and tomboy haircut in an era of on-screen voluptuous dumb blondeness. '60s - Mia Farrow went from girl-next-door to style icon at the hands of Vidal Sassoon, and Twiggy electrified the modelling world with her golden halo cut. '00s - Keira Knightley's texturised elfin crop is young and funky and left longer through the crown and front sections. Colouring techniques have given short hair more impact then ever, adding light, texture, depth and contrast.

3. Sex-kitten luxe

Naughty-but-nice styles inspired by the sensuality of France's New Wave cinema electrified the rock 'n' roll years and still remain a potent man-magnet.

Defining moments:
'50s - Bottle blonde Brigitte Bardot was the embodiment of uninhibited sexuality and a face that launched a thousand bouffant hairstyles. '90s - Claudia Schiffer – the German supermodel's impeccable glamourpuss look was BB-retro with a Teutonic twist. '00s - Everyone from Britney to Kate Moss loves the va-va-voom volume and brilliant blonde combo. Root lift has become ultra-fashionable and mousse and diffusers are again in daily use.

4. Hippie chic
A more earthy and ethereal interpretation of the '60s Kings Road dolly-bird look.

Defining moments:
'60s - Just-out-of-bed hair, goatskins, beads and plenty of eyeliner defined the spirit of free love. '00s – Sienna Miller's tousled tresses recall the festival child of the psychedelic era, but her subtle, blended highlights add polish and modernity to boho heritage.

5. From folk heroine to Friends

Straight hair was deeply unfashionable at the start of the century, but the epitome of perfection at the end of it.

Defining moments:
'70s - Peace loving Pocahontas's such as Cher embraced the middle parting and pin-straight waist-length tresses. '90s - The Jennifer Aniston post-Rachel phenomenon made hair straighteners the must-have styling tool and as her locks became longer, sleeker and more sun-kissed with each series, the more we aspired to this look.

6. Rebel, rebel
The mullet bi-level cut fuses a short spiky top and sides with a longer back section.

Defining moments:
'70s - While Ziggy played guitar, David Bowie sported a flaming orange mullet and rock chicks like Suzi Quatro followed suit. '80s - It wasn't just Kim Wilde who loved this heavily texturised bad-girl-blonde look: almost every Aussie soap star and footballer you could name succumbed to its dubious appeal. '00s - On the GMTV sofa, thanks to unlikely radical Lorraine Kelly, on the catwalks, courtesy of model Fanni Bostrum, and on any TV reality show set in a salon. Worn longer all over with more tendrils and texture, it's much more feminine these days.