London -- Britain's youngest royal, Prince Louis, turned one on Tuesday, but the world was anxiously awaiting news from his aunt and uncle, Prince Harry and Meghan Markle. The Duke and Duchess of Sussex are expecting their first child any day now.

Royal births have been a source of palace and international intrigue for centuries, so Harry and Meghan's decision to ditch decades of etiquette has come as a surprise to some, but it's certainly not the first time a "new" royal has broken with tradition.

Princess Elizabeth, as Queen Elizabeth II was known when she was born back in 1926, was part of the push to end an awkward, ancient, royal birthing protocol. Her own home birth had to be witnessed by a government minister over fears a potential heir to the throne could be swapped out for an imposter.

Queen Elizabeth's first-born son Charles was born by Cesarean at Buckingham palace. His sister and brothers were born there too but all of their children would usher in a new era of hospital births. Prince William was the first direct heir to the British throne to have been born in a medical ward and was introduced to the world on the hospital's front steps.

"Actually Diana found it very stressful. And then they drove away and the car went around the corner and she burst into tears," said royals biographer Ingrid Seward.

But two years later she faced the photographers again, after the birth of Prince Harry. And a couple of decades later, Prince William and Kate, the Duchess of Cambridge, introduced their first child, George, on the very same steps.

The rules of succession have also changed, allowing Princess Charlotte – William and Kate's second child – to maintain her position ahead of her younger brother, Prince Louis, who was born a few years later.

Harry and Meghan, the Duke and Duchess of Sussex, are choosing to have a much more private birth closer to their home in Windsor, where they married last year. And the first we'll see of their little one won't be hours, but more likely days after the arrival.

"It's sad for royal followers," Seward said. "Because we all want to enjoy this royal baby with them, but I think everybody completely understands their decision."

One tradition Harry and Meghan are keeping: a public notice is expected to be stuck on an easel at the gates of Buckingham Palace in London announcing the birth. And in a sign of our times, we can expect an Instagram post to follow.