Her mother, a Belgian "lady of rank," was the sister of Baron Le Roy Gaussandri, Minister of Public Instruction in Brussels during King Louis Philippe's reign.

[3] Reboux made a name for herself in millinery in Europe and the United States and was nicknamed "Queen of the Milliners.

[12] During the year 1898, Reboux employed 150 women, and she was appointed to represent Parisian commerce at the Paris World's Fair of 1900.

Reboux is also given credit for designing the iconic, unstructured, felt cloche "helmet" hat that first appeared in the 1920s when Lucienne Rabaté [fr] took the direction of the house.

Lucienne would create the hat by placing a length of felt on a customer's head and then cutting and folding it to shape, making the brand Reboux was one of the leading exponents of the form.

[14][23] The continued business of Caroline Reboux was well known for making the felt cloche, which remained "the status symbol of fashion for many years.

[24] Wallis Warfield Simpson, Duchess of Windsor, wore a blue Mainbocher outfit and a halo hat by Reboux for her wedding to the former King of England, Edward VIII at the Château de Candé in 1937.

[25] German-born American actress and singer Marlene Dietrich was a faithful customer of Reboux, from whom she bought her trademark berets.