9. Pierre Casiraghi
What a difference a decade makes! Back in 2004, Monegasque royal Pierre Casiraghi was just a 17-year-old boy who rocked long wavy hair and glasses. These days, the royal is often seen sporting a shorter 'do and facial hair. In 2015, Pierre tied the knot with Beatrice Borromeo and later welcomed children Stefano and Francesco. Pierre is the youngest son of Princess Caroline and the late Stefano Casiraghi. Sadly, Stefano died in 1990 when he flipped his speedboat while defending his title in a world championship race.