Question

What happened when jean-antoine watteau submitted the above piece to the royal academy of painting?

Answer 1

Jean-Antoine Watteau is the founder of the French Rococo style of painting.
When Jean-Antoine Watteau submitted the piece "The Embarkation for Cythera" from 1717 to the Royal Academy of Painting, the Academy was so impressed that it created a new category of subject matter to accommodate the painting. 

Answer 2

The Academy was so impressed that it created a new category of subject matter to accommodate the painting.