The Bra Turns 100: It's A Century Since Mary Phelps Jacobs Invented The Brassiere (PICTURES)

It’s time to say thanks for the mammaries and all the support – Wednesday marks the 100th birthday of the bra.

It was a century ago that New York socialite Mary Phelps Jacob invented the first modern brassiere after finding she had no suitable undergarments for a recently purchased sheer evening gown.

Unhappy with how the dress looked over a chunky whalebone corset, the 19-year-old improvised with a pair of silk handkerchiefs and a length of pink ribbon, and lo, the bra was born.

Over-the-shoulder-boulder-holders are a century old

Lingerie maker Simone Pérèle points out that the modern version of the bra as we know it did not appear until the 1930s, with the gradual addition of cup sizes, strapless models, and cone shapes as the industry wheels turned, but mighty oaks from little acorns did most certainly grow.

The momentous day was marked in Britain today with a segment on Lorraine Kelly’s ITV show, er, along the revelation that the host wears her own bra in bed every night ('I thought everybody did', she protested).

Stylist Tabitha Somerset-Webb showcased the best bras on the market and pointed out one in two British women are wearing the wrong size.

The patent for Mary Phelps Jacob's invention

She also urged women to be re-measured every six months.

The advice comes as it emerged British breasts are getting bigger – with ladies living in the North, the Midlands and Ireland leading the charge.

Busts have grown by three sizes in just two years, with the best-selling bra size going up from a 34B to a 34DD. And our cups are truly running over in Wales – with the most popular size being an E.

HuffPost UK Lifestyle spoke to Nicola Adams from Tallulah Lingerie to find out why bras have changed in the past 100 years.

"Bras has evolved over time to suit fashion trends," she explained. "Outerwear influences the style of lingerie women want and need for their foundations, plus lingerie will give different shapes depending on style."

Nicola said that above all modern women want comfort and support from their bras.

She told HuffPost UK Lifestyle: "There are so many collections on offer today that bras don't need to be ugly to be supportive. As long as women are in the correct bra size, then their bra will be comfortable whatever the style."

(FYI for anyone who feels like getting pedantic, Jacobs' invention was the first to be patented, scraps of ancient lingerie from the 1400s were discovered by archaeologists in an Austrian castle last year.)

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