Skip to main content

French Evening Gown

to
627
14
49
7,156
3,183
6
13
167
145
63
318
612
1,109
1,999
2,027
10
9,995
380
20
1,167
1,007
864
654
442
6,230
3,287
10,328
10,316
39
37
7
Sort By
Ted Lapidus Haute Couture Silk and Velvet Dress, Size 36FR
By Ted Lapidus, Ted Lapidus Haute Couture
Located in SAINT-OUEN-SUR-SEINE, FR
Ted Lapidus Haute Couture - Dress composed of velvet and silk taffeta. No composition or size tag, it fits a size 36FR. Additional information: Dimensions: Shoulders: 39 cm (15.35"...
Category

1980s French Evening Dresses

Yves saint Laurent Haute Couture Black Dress
By Yves Saint Laurent
Located in SAINT-OUEN-SUR-SEINE, FR
Yves Saint Laurent Haute Couture - Very nice dress in black wool crepe, fastening with a slanting snap closure that continues on to the wrap skirt. The waist is underlined with a ve...
Category

1990s French Evening Dresses

Yves Saint Laurent Haute Couture Black Dress
By Yves Saint Laurent
Located in SAINT-OUEN-SUR-SEINE, FR
Yves Saint Laurent Haute Couture - Dress composed of black wool cheesecloth and velvet. It fastens at the front with a series of buttons. Ribbon N°63982. No composition or size tag, ...
Category

1990s French Evening Dresses

Jean Patou Haute Couture Silk Chiffon Butterfly Pattern Dress
By Jean Patou
Located in SAINT-OUEN-SUR-SEINE, FR
Jean Patou Haute Couture (Ribbon 98734) - Silk chiffon dress trimmed with lurex and a butterfly pattern. No composition or size tag, it fits a size 34FR/36FR. Additional information...
Category

1960s French Evening Dresses

Balmain Wool and Silk Black Dress
By Balmain
Located in SAINT-OUEN-SUR-SEINE, FR
Balmain - Dress composed of wool and silk. No composition or size tag, it fits a size 36FR/38FR. Additional information: Dimensions: Shoulders: 41 cm (16.14"), Bust 42 cm (16.53"),...
Category

Early 2000s French Evening Dresses

Christian Lacroix Haute Couture Two-Tone Silk Jumpsuit
By Christian Lacroix
Located in SAINT-OUEN-SUR-SEINE, FR
Christian Lacroix -Haute Couture two-tone silk jumpsuit sewn onto the bust with a jewel. No size label or composition, it corresponds to a 36FR. Additional information: Dimensions:...
Category

Early 2000s French Evening Dresses

Louis Féraud Haute Couture "Universal" Dress Spring/Summer show, 1991
By Louis Feraud
Located in SAINT-OUEN-SUR-SEINE, FR
Louis Féraud - Organized dress embroidered with mother of pearl buttons. No size indicated, it corresponds to a 34FR/36FR. Pretty Woman" collection, "Universal" modem, Haute Couture ...
Category

1990s French Evening Dresses

Velvet dress JC de Castelbajac
By Jean-Charles de Castelbajac
Located in SAINT-OUEN-SUR-SEINE, FR
Castelbajac - Velvet long dress decorated with sequins. No size label or composition, it corresponds to a size 36FR/38FR. Additional information: Dimensions: Shoulder width: 40 cm,...
Category

1990s French Evening Dresses

Pierre Cardin Wool Dress, Size 38FR
By Pierre Cardin
Located in SAINT-OUEN-SUR-SEINE, FR
Pierre Cardin - Wool dress Closing with a side zip. No composition or size tag, it fits a size 38FR. Additional information: Dimensions: Bust 45 cm (17.71"), Waist: 36 cm (14.17"),...
Category

1970s French Evening Dresses

Louis Féraud Haute Couture Satin Dress Embroidered with Mother of Pearl Buttons
By Louis Feraud
Located in SAINT-OUEN-SUR-SEINE, FR
Louis Féraud -Satin dress embroidered with mother of pearl buttons. It is accompanied by a beige muslin stole also embroidered. No size indicated, it corresponds to a 34FR/36FR. Co...
Category

1990s French Evening Dresses

Black Silk with Gold Sequins Dress, 1930 s
Located in SAINT-OUEN-SUR-SEINE, FR
30's black silk dress topped with a top fully embroidered with gold sequins. No composition label or size listed, it fits a 38FR. Additional information: Dimensions: Chest: 40 cm, ...
Category

1930s French Evening Dresses

Dior Haute Couture Dress in Embroidered Silk, Size 36FR
By Gianfranco Ferré for Christian Dior, Christian Dior
Located in SAINT-OUEN-SUR-SEINE, FR
Haute-Couture dress in embroidered silk. The top is lined with nude silk, the bottom is lined with black acetate. No composition, brand or size tag, it fits a size 36FR. Haute-Coutur...
Category

1990s French Evening Dresses

Superb 1980s Vicky Tiel Couture "Sara" Metallic Gold Lame Dress with Bolero (38)
By Vicky Tiel
Located in Port Hope, ON
Outstanding piece in excellent condition. The dress is boned to the waist and has a an inset bra. The permanent pleats of the skirt complement the gathers to be found at the bust and...
Category

1980s French Evening Dresses and Gowns

Gold and Silver Dress Paco Rabanne, Size 36FR
By Paco Rabanne
Located in SAINT-OUEN-SUR-SEINE, FR
Paco Rabanne -Long silver and gold coated canvas dress embellished with gold metallic plates. No size or composition label, it fits a size 36FR. Additional information: Dimensions...
Category

1980s French Evening Dresses

Chanel Black Tweed and Metallic Sleeveless Midi Dress Size 40
By Chanel
Located in Beverly Hills, CA
lining with Chanel logo pattern Made in France
Category

21st Century and Contemporary French Evening Dresses

Jean Patou Haute Couture Silk Dress, Size 36FR
By Jean Patou
Located in SAINT-OUEN-SUR-SEINE, FR
Jean Patou Haute Couture - Chiffon silk dress overstiched with threads, velvet and lurex. No composition or size tag, fits 36FR. Additional information: Dimensions: Chest: 45 cm...
Category

1970s French Evening Dresses

Leonard Paris Floral Silk Lace Inset Maxi Dress, 1990s
By Leonard of Paris
Located in Boca Raton, FL
Synonymous with luxury and innovation, Léonard Paris is known for their silk jersey dresses and signature orchid prints. Referring to himself as “... a couturier with a sense of mark...
Category

1990s French Evening Dresses and Gowns

John Galliano knit jersey maxi dress with patchwork motif, fw 2004
By John Galliano
Located in London, GB
▪ John Galliano knitted maxi dress ▪ Fall-Winter 2004 ▪Expertly crafted from knit cotton jersey, showcasing an allover woven patchwork print featuring tartan and floral squares in de...
Category

Early 2000s French Evening Dresses and Gowns

Sonia Rykiel Paris, Crushed Velvet Dress
By Sonia Rykiel
Located in Sharon, CT
Of a 'crushed' black velvet. Approx. size 6. Dropped waist in front by design. Padded shoulders. Bow in front below neckline. Length in front 50", length of back 53".
Category

1980s French Evening Gowns

Christian Lacroix Haute Couture Chiffon Dress, Spring-Summer 1990
By Christian Lacroix
Located in SAINT-OUEN-SUR-SEINE, FR
Christian Lacroix Haute Couture - Silk chiffon dress decorated with a brooch made of gilded metal paved with rhinestones. No composition or size tag, it fits a size 38FR. Haute Cou...
Category

1990s French Evening Dresses

Balenciaga multicoloured Viscose Dress NWOT
By Balenciaga
Located in Capri, IT
Balenciaga multicoloured Viscose Dress NWOT Totally made in france in FR 42 size Never used
Category

21st Century and Contemporary French Evening Dresses and Gowns

Christian Dior Black Wool Midi Dress, Size 6
By Christian Dior
Located in Beverly Hills, CA
Product details: The dress features crew neck line, short balloon sleeves, midi length flare skirt, rear zip closure and knit finish.
Category

2010s French Evening Dresses and Gowns

Vintage Yves Saint Laurent Silk Violet Bustier Dress, 1980s
By Yves Saint Laurent
Located in New York, NY
Beautiful Vintage Yves Saint Laurent silk bustier violet dress with a small drapery in front. Edition Soir. The inner corset tightly fixes the bustier on the chest. Fastens with a ...
Category

1980s French Evening Dresses

Chanel 2008 Tweed Dress with Chains EU 38
By Chanel
Located in US
detailing. Dress is fully lined and has a back zipper fastening. Labeled size 38, made in France, composed
Category

21st Century and Contemporary French Evening Dresses and Gowns

Jean Paul Gaultier Denim Raw Edges Dress With Fringe Panels
By Jean Paul Gaultier
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Jean Paul Gaultier blue denim dress featuring vertical panels with raw edges that detach at skirt hemline which creates a fringe ef...
Category

21st Century and Contemporary French Evening Dresses and Gowns

Herve Leger Striped Asymmetrical Bodycon Dress 1990 s
By Herve Léger
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Herve Leger black dress featuring an asymmetrical hem line, striped body, and spaghetti straps. Herve Leger Size X-Small Rayon, El...
Category

1990s French Evening Dresses and Gowns

Balmain by Christophe Decarnin destroyed jersey and metal mini dress, ss 2010
By Balmain
Located in London, GB
▪ Balmain destroyed khaki green jersey mini dress ▪ Designed by Christophe Decarnin ▪ Rippings and holes allover the fabric ▪ Destroyed metal chainmail applied on top ▪ Wide neck ▪ ...
Category

2010s French Evening Dresses and Gowns

Balenciaga Brown Wool Dress NWOT
By Balenciaga
Located in Capri, IT
Balenciaga Brown Wool Dress NWOT Brown Wool dress totally made in france, still with tags, size
Category

21st Century and Contemporary French Evening Dresses and Gowns

Balenciaga Brown Wool Dress NWOT
Balenciaga Brown Wool Dress NWOT
$282 Sale Price
33% Off
Deco Beaded Dot Dance Dress
Located in New York, NY
French art deco dress of black beaded dots which graduate from small to large across bodice and
Category

1930s French Evening Dresses and Gowns

Thierry Mugler Vintage Heather Brown Silk Bustier Dress with Gold Toned Claws
By Thierry Mugler
Located in Nice, FR
Made in France. Size label reads : 38. Please refer to measurements. Composition tag reads : 100
Category

20th Century French Evening Dresses and Gowns

1960 s Pierre Cardin Purple Dress with Chrome Keyhole Neckline
By Pierre Cardin
Located in New Hope, PA
Pierre Cardin designed this purple sleeveless A-line dress in the 1960's. The chrome accented keyhole neckline makes it just as popular today. The purple wool keyhole is edged with...
Category

1960s French Evening Dresses

Chanel Black Knit Wet Look Cage Dress
By Chanel
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Chanel black viscose knit cocktail cage dress featuring vertical bands, black wetlook trim, black and gold "CC" buttons, pleated sk...
Category

20th Century French Evening Dresses and Gowns

Balenciaga By Ghesquiere Off-White Box Pleat Dress 2006
By Balenciaga
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Nicolas Ghesquière for Balenciaga off-white silk and wool dress featuring a silk top, large buttons, box pleat skirt and above the...
Category

Early 2000s French Evening Dresses and Gowns

Paul Daunay Couture green floral silk cocktail dress, circa 1952-57
By Paul Daunay
Located in London, GB
meticulous craftsmanship of the era's haute couture designs. This evening dress serves as a testament to the
Category

1950s French Evening Dresses and Gowns

Sonia Rykiel blu dress
By Sonia Rykiel
Located in Capri, IT
Sonia Rykiel blu dress totally made in france in size S Composition: Cotton
Category

1980s French Evening Dresses and Gowns

Sonia Rykiel blu dress
Sonia Rykiel blu dress
$184 Sale Price
44% Off
Chantal Thomass Black Bodycon Halter Dress With Ruffles 1992
By Chantal Thomass
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Chantal Thomass black ribbed body-con dress with halter top, ribbed stretch body, fitted body, lace ruffle back and sleeves, and lo...
Category

1990s French Evening Dresses and Gowns

Lanvin One Shoulder Silk Mini Red Dress, 2010
By Lanvin Paris
Located in New York, NY
Lanvin mini draped one-shoulder dress by Alber Elbaz in red color. Collection 2010 Fabric: 100% silk Size: 38 FR (M) Condition: Perfect ........Additional information ........ - P...
Category

21st Century and Contemporary French Evening Dresses

1970 s SONIA RYKIEL black bias-cut layered silk dress
By Sonia Rykiel
Located in San Fransisco, CA
Black, bias-cut silk dress with uneven hemline and cape designed by Sonia Rykiel dating to the 1970's. No size is indicated however this is best suited for a US 2-4. Approximate meas...
Category

1970s French Evening Dresses and Gowns

A vintage 1960s Courreges cream Wool and Silk Dress Model 29074
By André Courrèges
Located in London, GB
A chic dress by French designer Courreges. In a cream wool with silk lining, this dress is perfect
Category

1960s French Evening Dresses and Gowns

Jacqueline de Ribes Black Silk Chiffon Slip Dress w/ Caftan
By Jacqueline de Ribes
Located in Los Angeles, CA
This is a lovely 2 piece evening ensemble from Jacqueline de Ribes. The dress is a spaghetti strap
Category

Late 20th Century French Evening Gowns

Herve Leger Bandage Dress Embroidered with Beads, 2000s
By Herve Léger
Located in New York, NY
Herve Leger bandage dress embroidered with beads. Period: 2000s Sleeveless, fastens with a zipper at the back. Size: XS Condition: good, here are a few stains. ........Additional i...
Category

Early 2000s French Evening Dresses

Geoffrey Beene Sequin Strapless Mini Dress
By Geoffrey Beene
Located in Scottsdale, AZ
This has to be yours for your next special event! This hot number is done by the iconic Geoffrey Beene, known as one of the United State's design pioneers and known for his true icon...
Category

1980s French Evening Dresses and Gowns

Roland Mouret Navy and Black Dress, Size 38
By RM by Roland Mouret
Located in Beverly Hills, CA
featured rear zip closure and mid length. Made in France.
Category

Late 20th Century French Evening Dresses and Gowns

White double-breasted jacket with silver metal buttons Claude Montana
By Claude Montana
Located in Saint-Ouen-Sur-Seine, FR
White double-breasted jacket with silver metal buttons. Fabric composition: 90% acetate, 10% silk. Lining: 61% rayon, 39% Cupro SIZE 38 (M)
Category

1980s French Evening Gowns

Christian Dior by John Galliano Brown and Cream Suede Dress and Jacket, FW 1999
By John Galliano for Christian Dior, Christian Dior
Located in London, GB
-breasted jacket ▪ Size: FR 38 - UK10 - US6 ▪ Made in: France ▪ Condition: Very Good ▪ Mannequin: 183 cm
Category

1990s French Evening Dresses and Gowns

Chanel Lace Striped Camellia Empire Dress S/S 1988
By Karl Lagerfeld for Chanel, Chanel
Located in Boca Raton, FL
In addition to other signature design details, the camellia flower is another symbol of Chanel. Supposedly her favorite flower, some say due to being given a bouquet by a lover while...
Category

1980s French Evening Dresses and Gowns

Lanvin long velvet dress 60s/70s
By Lanvin Paris
Located in Rubiera, RE
LANVIN 22. Faubourg St. Honoré _ PARIS 60s/70s Long printed velvet dress with large shocking pink and ruby red roses on a brown and gray background Round neck, basque around the wai...
Category

1970s French Evening Dresses and Gowns

Christian Dior Green Leopard One Shoulder Sari Dress 2008
By Christian Dior
Located in Los Angeles, CA
Resurrection is excited to offer a vintage Christian Dior green dress featuring, a leopard print, rhinestones along the top of the dress, a chiffon shoulder overlay, and button closu...
Category

Early 2000s French Evening Dresses

Christian Dior by John Galliano taupe open-knit dress, ss 2001
By Christian Dior, John Galliano for Christian Dior
Located in London, GB
▪ Christian Dior taupe open-knit dress ▪ Designed by John Galliano ▪ Spring-Summer 2001 ▪ Double-layered ▪ Multiple shoulder straps ▪ Figure-hugging fit ▪ Deep v neckline ▪ Asymm...
Category

Early 2000s French Evening Dresses and Gowns

Balenciaga By Ghesquiere Black Peplum Coat Dress
By Balenciaga
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Balenciaga by Nicolas Ghesquière black coat dress featuring a high collar, ruffle insets in the bodice and sleeves, a fitted waist,...
Category

Early 2000s French Evening Dresses and Gowns

Balenciaga by Ghesquiere Black Cocktail Mini Dress 2007
By Balenciaga
Located in Los Angeles, CA
Resurrection Vintage is excited to offer a vintage Balenciaga by Nicolas Ghesquiere black viscose cocktail dress featuring an empire waistline, drape skirt, bubble hem, and side zipp...
Category

Early 2000s French Evening Dresses and Gowns

1970s Guy Laroche Couture Coral Red Feather Dress
By Guy Laroche
Located in London, GB
This original 1970s red feather dress ensemble by Guy Laroche is a high-end boutique piece or demi couture order and the perfect statement piece for any event or party. The ensemble ...
Category

1970s French Evening Gowns

1970s Navy Jersey Haute Couture Grecian Style Dress
Located in London, GB
This mid to late 1970s navy and sequin detail Grecian dress is a show stopping unlabelled couture piece. It is skilled work and has mostly been made by hands trained in haute coutur...
Category

1970s French Evening Dresses

Saint Laurent YSL One shoulder Black Velvet Metallic Layered Dress, 1980s
By Yves Saint Laurent
Located in Boca Raton, FL
A designer who in many ways was ahead of his time, YSL seamlessly has evolved his aesthetic from traditional to modern and back again. Following his themed Russian and Opium collecti...
Category

1970s French Evening Dresses and Gowns

Lanvin by Alber Elbaz Brown Silk Dress
By Lanvin Paris, Alber Elbaz
Located in Beverly Hills, CA
Lanvin by Alber Elbaz Brown silk cocktail dress with black spaghetti strap. Dress drop waist fastener that is adjustable.\ Fit size Small- Medium ( 2/4/6)
Category

Early 2000s French Evening Dresses and Gowns

80s Yves Saint Laurent Couture Black Velvet Cocktail Dress
By Yves Saint Laurent
Located in Beverly Hills, CA
1980s Yves Saint Laurent Couture Black Velvet Long sleeve cocktail dress. Bust: 40”/ waist: 30/ Hip: 40” /sleeve: 23”/ Dress length: 38”
Category

1980s French Evening Gowns

Givenchy Haute Couture Black Multi Color Dots Vintage Silk Dress
By Givenchy
Located in Beverly Hills, CA
Vintage Givenchy Couture black silk matelasse cocktail dress with asymmetrical neckline and multi color irregular shaped dots in yellow, red, purple and green. On the front of the d...
Category

1980s French Evening Dresses

  • 1
  • ...
Get Updated with New Arrivals
Save "French Evening Gown", and we’ll notify you when there are new listings in this category.

French Evening Gown For Sale on 1stDibs

You are likely to find exactly the vintage or contemporary french evening gown you’re looking for on 1stDibs, as there is a broad range for sale. Our collection includes a variety of colors, spanning Black, Brown, Gray and more. Finding the perfect french evening gown may mean sifting through those that were made during different time periods — popular versions were made as early as the 18th Century and a newer one, made as recently as the 21st Century, can also be found on the site. Making an accessory such as this has likely been a part of the legacy of many fashion designers, but those produced by Christian Dior, Carven and Dolce Gabbana are consistently popular. Finding a french evening gown for sale for women should be easy, but there are 5 pieces available to browse for men as well.

How Much is a French Evening Gown?

On average, a french evening gown on 1stDibs sells for $1,535, while they’re typically $225 on the low end and $18,397 for the highest priced versions of this item.

Finding the Right Evening-dresses for You

With entire museum exhibitions dedicated to examining fashion designers and their creations, we’re finally recognizing that costuming is art. Evening dresses over time have conveyed specific statements about social class, position and beliefs. Fashion is a powerful means of self-expression, and sophisticated vintage evening dresses and gowns by our favorite couturier play no small role in making us feel wonderful but, perhaps more importantly, making us feel like ourselves.

In the 16th century, dresses and gowns were so important that England's Queen Elizabeth I defined rules about what dresses women could wear — guidance included long skirts and fitted bodices. Forward-thinking designers have responded to this history.

Gabrielle “Coco” Chanel reimagined traditionally masculine garments for feminine shapes, and her elegant evening dresses and gowns promoted comfort and grace in women’s wear that had been dominated in the previous century by layers of fabric. Christian Dior's gowns celebrated luxury and femininity in the late 1940s — and gave to women the gift of glamour they’d lost in the miserable years of the war. French fashion designer Yves Saint Laurent introduced innovative and highly coveted dress designs in the 1960s while at the same time challenging sexist stereotypes about which members of society could wear tuxedos.

Works by unconventional British designer John Galliano — featured in houses like Givenchy and Dior — redefined limits that dressmakers faced in terms of material, construction and vision during the late 20th century. From his embroidered absinthe-green Oscars gown for actress Nicole Kidman to the iconic sleeveless Dior newspaper dress that Sex and the City’s Carrie Bradshaw made famous, Galliano’s intricate and multifaceted work is reliably collectible and newsworthy

Today’s designers target an increasingly broad audience with their boundary-crossing work, and their tendency to play off of each other’s ideas means that every walk down the runway is also a walk through an entire history of fashion design and dress craftsmanship.

Whether you gravitate toward backless maxi dresses or silk charmeuse gowns by Alexander McQueen or embellished, ruffled floral-print designs by Chloe or Versace, there is an extraordinary collection of vintage and designer evening dresses and gowns waiting for you on 1stDibs.

Questions About French Evening Gown
  • 1stDibs ExpertOctober 7, 2024
    The difference between an evening dress and an evening gown is length. An evening gown is generally a full-length garment that falls between the ankles and the floor. An evening dress is a semi-formal or formal dress designed to be worn at night or on special occasions. Evening gowns are one type of evening dress, and you can also find examples with mini, knee-length and midi-length hemlines. Shop a wide range of evening gowns and other evening dresses on 1stDibs.
  • 1stDibs ExpertOctober 7, 2024
    There really isn't a difference between a cocktail gown and an evening gown. Both terms describe a full-length formal dress designed for evenings and special occasions. On the other hand, a cocktail dress or evening dress is a less formal garment that usually falls between just above and just below the knees and is suitable for evening wear. Explore a wide variety of cocktail dresses and evening gowns on 1stDibs.
  • 1stDibs ExpertNovember 2, 2021
    The best color for an evening gown is a matter of preference. Evening gowns are popular in a variety of colors, including black, red, purple, green, blue, pink and more. Whether you gravitate toward backless maxi dresses or silk charmeuse gowns by Alexander McQueen or embellished, ruffled floral-print designs by Chloe or Versace, there is an extraordinary collection of vintage and designer evening dresses and gowns waiting for you on 1stDibs.

Read More

Barbra Streisand Channeled Klimt’s ‘Woman in Gold’ in This Shimmering Dress

Costumer to the stars Ray Aghayan brought the famed painting to life with his spectacular design.

A Chanel Obsessive’s Cache Extends Well beyond Her Walk-In Closet

From handbags and heels to jackets and jewels, Sharon Coplan Hurowitz has a deep admiration for (and collection of) all things Chanel.

Behind the 1970s and ’80s Glam of ‘Halston’ with the Hit Show’s Costume Designer

Jeriana San Juan explains how she undertook the intimidating project of designing costumes for the new Netflix series about the New York fashion legend. (Hint: She found vintage Halston on 1stDibs!)

A Short History of Capri Pants, on the 100th Birthday of Their Inventor

Once considered a controversial item of clothing, fashion designer Sonja de Lennart's creation is now a bona fide classic.

How the Chanel Jacket Forever Changed What Women Wear

The classic tweed garment has been a wardrobe staple of chic women around the world since the 1950s.

A Pair of Shoes — Heels or Flats — Can Tell an Impactful Story

Amanda Benchley and Bridget Moynahan teamed up to explore the relationship between powerful women and their most significant footwear.

You Saw It at the Met Ball. Here’s What Camp Fashion Is Really About

This year's Costume Institute exhibition is all about embracing the eccentric.

The V&A Takes a Fresh Look at the New Look’s Pioneering Progenitor, Christian Dior

Ballrooms, Bar Suits and British royals — in a sweeping exhibition, the London museum looks back on 70 years of the French fashion house, as well as its illustrious founder and his fondness for the United Kingdom.