Prince Harry has spoken a great deal about his perceived role as the 'Spare' in relation to the royal line of succession. In fact, he went so far as to title his tell-all memoir as such, and claimed in the book that his father King Charles commented to Princess Diana at Harry's birth: "Wonderful! Now you've given me an heir and a spare – my work is done." Harry has also spoken about his fears for William and Kate's youngest children, Princess Charlotte and Prince Louis , who will fall behind