The Fete Nationale or Bastille Day is the biggest annual celebration not only in Provence but France in general. It's called Bastille Day because of the storming of the Parisian prison, the Bastille, and freeing the prisoners inside. This event was symbolic for the French revolution, and it marks the formation of the republic.
Every year on July 14th, celebrations with music, dances, parades, fireworks, and French flags everywhere take place all around the country. In Provence, they also include village festivals, street markets, and bull fights. These fights aren't real fights but rather games where the participants have to take a rosette from the bull's horn and get away as safely as possible.
Aside from that, there are also herdings of bulls and horses through the streets by cowboys in traditional costumes. All this ends in big parties with great food and a fun atmosphere.