The tower was the symbol of the new royal power reigning over Carcassonne.
The enormous cylindrical mass of the Vade tower was constructed to be a completely independent defence element, with its own baker's oven, a well, and latrines. It could hold a siege without help from the other parts of the fortifications ! The garrison could stand even if the outer walls were lost, and the tower then was a threat to the back of the enemy who was launching an attack on the inner walls.
The name "Vade" comes from an occitan word "vada", that means "watch, surveillance".
In the Middle Ages, the inhabitants of Carcassonne used to hang a "papegai", a big wooden bird, on the top of the tower. The archers practised their skill on this target.
A competition was organised every year in May. The best archer, who could shoot down the bird, was chosen as the King of the Papegai.