...The Kingdom will fall and the Crown with it.
For as long as the Tower has stood, the legend has been that when the ravens leave the crown will fall. Today, it is still widely recited and six ravens must be kept within its grounds at all time. To ensure the flock, a spare is kept and each bird regularly has its wings clipped to keep them close by.
Their importance is so revered that they are viewed as servants of the nation, and enlisted in the army with the same papers as any other soldier.