According to Prince Harry writing in his shock memoir Spare, then-Prince Charles told Princess Diana after she gave birth to their youngest son, "Wonderful! Now you've given me an heir and a spare—my work is done."
Though we will never know whether this exchange truly happened or not, it illustrates one certainty among the British Royal Family: Over the course of history, there was often a "spare" who was pitted against the heir to the throne, and who became rebellious as a way to create their own identity.
