Royal wedding 2018: Will Meghan Markle's gown follow the unspoken royal dress code?

With only hours to go until the wedding of Prince Harry and Meghan Markle, the biggest fashion moment of the year remains a secret.

The secret is: Meghan's wedding dress.

What will Meghan wear?

What will Meghan wear?

Once upon a time... royal wedding dresses were richly coloured

Queen Mary I was married in purple in 1554 - reserved exclusively for royals

In 1816 Princess Charlotte wore real silver thread with silver embroidery

Then Queen Victoria chose a simple white dress in English silk and lace

And set the pattern for white weddings ever after

The Queen Mother broke the mould in a loose flapper-era gown

But there are some style rules almost all royal dresses follow

No knees, please - royal dresses are nearly always full length

Since the 50s, skirts have slowly increased in volume

Sweden's Crown Princess Victoria went for an 'off-the-shoulder' look

But sleeves are still the done thing for most royal brides

A couple more finishing touches help define the royal look...

A train adds a sense of grandeur as you glide to the altar

And a veil remains quintessential for a royal wedding - Kate wore one too

The timeless princess role-model remains Grace Kelly in a high neck and full sleeves

Quite different from the layered tulle dress Meghan wore as an actress in Suits

But maybe she has a few surprises for us - we'll soon find out

If you can't see the explainer above, follow this link.

Royal wedding: What we know so far

Who is Meghan Markle?

Four vintage royal wedding gowns

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