It's finally happening: Prince William and Kate Middleton are expecting their first little royal. Kate's pregnancy is a momentous occasion — and not just because of the tabloid hype. Her child will be the all-but-inevitable heir to the throne — no matter the baby's gender — following Prince William, the eldest child of Prince Charles and Princess Diana, and William's father Charles, who is the eldest child of Queen Elizabeth II. As William and Kate's devoted public watches for the growing royal baby bump, let's take a look back at royal babies from generations past:

1927: Baby Elizabeth
According to this photo, the future Queen may have always had an affinity for fancy hats. Looking regal even for 1-year-old, little Princess Elizabeth takes a ride with her cousins around the grounds of Windsor Castle. (AP Photo)

1949: Baby Charles
Striking a most serious pose, 1-year-old Prince Charles of Edinburgh sits for an informal portrait with his proud mother. (AP Photo)

1982: Baby William 
Following in his father's footsteps, 6-month-old Prince William acquires a rather solemn look while posing with dad during the little heir's first public picture session at Kensington Palace. (AP Photo/David Caulkin)