Kate Middleton and Prince William Welcome Royal Baby ... It's a Boy!

It's a prince! On Monday, the world welcomed the newest addition to the royal family and the future heir to England's throne. Palace officials confirmed the arrival of His Royal Highness the Prince of Cambridge, born at St. Mary's Hospital at 4:24 p.m. BST, and weighing 8 lbs. 6 oz..

"We could not be happier," said Prince William in a statement released by the palace shortly after the birth of his son. He was at his wife's side during her delivery, unlike past royals. Both mother and child are doing fine, the palace confirmed, and are expected to leave the hospital on Tuesday evening (not before 6 pm BST) or Wednesday morning.

"Mother, son and father are all doing well this morning" palace officials stated in a press release on Tuesday. The name of the future monarch will be released "in due course."

"We would like to thank the staff at the Lindo Wing and the whole hospital for the tremendous care the three of us have received," said the Duke and Duchess of Cambridge in a statement released by the palace on Tuesday morning. "We know it has been a very busy period for the hospital and we would like to thank everyone — staff, patients and visitors — for their understanding during this time."

The newborn is officially called the Prince of Cambridge. He is the first royal to use that title in over 100 years.

"The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, Prince Harry and members of both families have been informed and are delighted with the news," according to the brief statement emailed to members of the press, many of whom have been camped outside of St. Mary's Hospital for days.

Prince Charles elaborated in a statement released through Clarence House. He said he is "enormously proud and happy to be a grandfather for the first time."

"Both my wife and I are overjoyed at the arrival of my first grandchild," he said. "It is an incredibly special moment for William and Catherine and we are so thrilled for them on the birth of their baby boy." The Duchess of Cornwall added: "It's wonderful for the grandfather. He's brilliant with children so he'll have a wonderful time."

Even President Barack Obama weighed in on the birth. "Michelle and I are so pleased to congratulate The Duke and Duchess of Cambridge on the joyous occasion of the birth of their first child," he said in a statement released through the White House. "We wish them all the happiness and blessings parenthood brings. The child enters the world at a time of promise and opportunity for our two nations. Given the special relationship between us, the American people are pleased to join with the people of the United Kingdom as they celebrate the birth of the young prince."

The birth marks a new era for not only the first-time parents but also the extended royal family. As third in line to succeed to the throne after his grandfather Prince Charles and his father, Prince William, he's the first baby born under new succession laws.

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The modernized bill amends a centuries-old policy, allowing the royal couple's first-born child the right to inherit the throne regardless of gender.

"Historically, this is huge," Victoria Arbiter, CNN's royal expert, told Yahoo! Shine. "In 60 or 70 years, this baby will be a monarch. It's also the first time since Queen Victoria that four generations of monarchs will be alive together."

It's been a long and sometimes rocky journey to the historic due date. Anticipation about the heir to the throne began well before the frenzy over rumored due dates and even before St. James's Palace officially announced the Duchess of Cambridge's pregnancy in December. From the first day of their marriage over two years ago, Prince William and Kate Middleton have had an audience of clock-watchers.

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But they have never let public expectations determine their personal timing. After their 10-year courtship, the couple put off parenthood to enjoy their first year as a married couple. In that time, Middleton flexed her philanthropic muscles and stepped into her late mother-in-law's shoes as an international fashion arbiter. She also weathered a paparazzi scandal, prompting the palace to tighten its reins on the press.

When it came to the big announcement about the couple's first child, there was only so much the royal family could control. (To quote the duchess herself, "Babies have their own agenda.") Before the official news broke, Middleton suffered acute morning sickness early in her first trimester. During her treatment at a central London hospital, pregnancy rumors reached a boiling point and the palace was forced to confirm what the public had long hoped.

"As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter," read the official statement from St. James's Palace.

The news rippled immediately through the retail industry. Collectibles marking the anticipated firstborn's arrival began rolling out by early 2013, as maternity designers elbowed each other for the chance to dress the mom-to-be. All told, the Centre for Retail Research predicts the royal birth could boost the British economy by nearly $400 million.

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Tragedy overshadowed the worldwide excitement when two Australian radio hosts pranked Middleton's hospital and the nurse who took the hoax call later committed suicide.

It was a sobering reminder of the impact of royal coverage on human lives. For the future monarch, it's an unfortunate part of the inheritance and of an unfathomable burden of power. 

Perhaps no one better understands this than the new dad, Prince William.

"Royal firstborns may get all the glory, but secondborns enjoy more freedom," Diana, Princess of Wales, said after giving birth to her second son, Harry. "My second child will never have quite the same sort of pressure that poor William must face all his life."

That firstborn pressure includes carrying the HRH title and the legacy that goes with it. In the distant future, the newborn is poised to be the supreme governor of the Church of England, head of the U.K. armed forces, and the head of state in 16 countries.

"One day, this baby will be an influence across the globe, a leader, and someone millions of people will look up to," said Arbiter. For now, however, he has two main responsibilities: eating and sleeping, just like any other baby.