The French used to be a lot more militant than they are now. I learned the words of the first verse in my high school french class, and remember most of it. The translation follows.

Bloodthirsty, no?

Let’s go children of the fatherland,

The day of glory has arrived!
Against us tyranny’s
Bloody flag is raised! (repeat)
In the countryside, do you hear
The roaring of these fierce soldiers?
They come right to our arms
To slit the throats of our sons, our friends!

Grab your weapons, citizens!
Form your battalions!
Let us march! Let us march!
May impure blood
Water our fields!

According to Britannica:

Bastille Day marks the anniversary of the fall on July 14, 1789, of the Bastille, in Paris. Originally built as a medieval fortress, the Bastille eventually came to be used as a state prison. Political prisoners were often held there, as were citizens detained by the authorities for trial. Some prisoners were held on the direct order of the king, from which there was no appeal.

During the unrest of 1789, on July 14 a mob approached the Bastille to demand the arms and ammunition stored there, and, when the forces guarding the structure resisted, the attackers stormed the prison and released the seven prisoners held there. The taking of the Bastille signaled the beginning of the French Revolution, and it thus became a symbol of the end of the ancien régime.