Who invented first cocktail dress and when?

It's impossible to definitively say who invented the first cocktail dress. There wasn't a single designer who created it, and the style evolved gradually over time.

Here's what we do know:

* The concept of cocktail attire emerged in the 1920s. This was a time of social change and evolving fashion, with women seeking more comfortable and practical clothes. The flapper era saw shorter hemlines and looser silhouettes, which paved the way for the cocktail dress.

* The term "cocktail dress" itself was coined in the 1930s. It was initially used to describe dresses that were more informal than evening gowns but still elegant enough for social events.

* Key designers who contributed to the development of the cocktail dress include:

* Coco Chanel: She introduced the little black dress in the 1920s, which became a cornerstone of the cocktail dress style.

* Elsa Schiaparelli: She experimented with innovative designs and fabrics, creating bold and playful cocktail dresses.

* Mainbocher: He designed the iconic "Mainbocher dress" in the 1930s, a simple but elegant sheath dress that was popular with socialites.

While specific inventors remain elusive, the cocktail dress emerged as a confluence of social trends, design innovation, and evolving fashion tastes in the 1920s and 1930s. It's a timeless silhouette that has remained a staple in women's wardrobes ever since.