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Mary-Kate (left) and Ashley, 1993

Pretty sure I just bought a fancier version of those sandals at Opening Ceremony.

Ashley (left) and Mary-Kate, 1999

Intentionally or not, they were about a decade ahead of the Carolyn Bessette-Kennedy style resurgence.

Ashley (left) and Mary-Kate, 2002

At fifteen years old, it was the last time MK & A made a public appearance in matching outfits.

Ashley (left) and Mary-Kate, 2001

They then moved on to reverse coordinating— this time in halter tops and wide leg pants, like two lost members of Destiny's Child.

Ashley (left) and Mary-Kate, 2003

Finally the girls graduated to totally different outfits, nailing all the 2003 staples at once: pointy toe flats, faded boot cut jeans, "going out" tops and a beret.

Ashley, 2005

Channeling Lily van der Woodsen even before Gossip Girl was a thing.

Ashley, 2005

Never in the tabloid bikini pages and famously covered-up on the red carpet, this side boob slip is—I think—the only one of its kind.

Mary-Kate, 2006

For a while, Mary-Kate stuck to a specific template: long bohemian dresses, eccentric accessories, beachy hair.

Mary-Kate, 2006

A crystal ball would've looked just as fitting as that clutch.

Mary-Kate, 2006

Fur and lace together, obviously.

Ashley, 2006

In the meantime, Ashley kept it polished: lots of Calvin Klein, a dash of red lipstick.

Ashley, 2007

Pairing Alaia accessories with t-shirts that come in three packs is maybe one of the more brilliant moves of all time.

Mary-Kate, 2007

So Grey Gardens and haunting. I feel like she wants to eat my soul.

Ashley (left) and Mary-Kate, 2007

Back in coordinating outfits: channeling Courtney Love and pissing off PETA.

Mary-Kate, 2008

A surprising one: so much more '70s preppy beach-y than most of her wardrobe.

Mary-Kate, 2008

Sure, it's the jacket. But it's also the sunglasses and the hair.

Mary-Kate (left) and Ashley, 2008

At the launch of their book Influence, the sisters stepped out in crisp, streamlined separates in neutral colors.

Mary-Kate (left) and Ashley, 2008

Ashley's shoes might be my favorite simple-but-not-boring black pumps ever.

Mary-Kate, 2009

A testament to the classic trench's versatility. Just add a smudge of black eyeliner and a pale lip, and it's more Kate Moss clomping around London than Mom running errands.

Mary-Kate (left) and Ashley, 2010

If I remember correctly, this is what inspired me to buy a leopard print coat.

Ashley, 2010

Color-blocking and print-mixing weren't really in her lexicon for a while.

Ashley, 2011

Maybe she just missed those head-to-toe matching twin outfits?

Ashley, 2011

Proof that petite girls can pull off super-voluminous looks, too.

Mary-Kate (left) and Ashley

Ashley can even elevate the suburban Mom look.

Ashley (left) and Mary-Kate, 2011

Sometimes a really amazing jacket stands out on the red carpet more than any of the gowns.

Ashley (left) and Mary-Kate, 2011

Celebrating their nomination for the CFDA's Womenswear Designer of the Year award, the girls made power dressing look really pretty.