While the coronation is a global event, it is also a family affair.

All eyes will be not just on Charles but also his sons William and Harry, who have faced ongoing tensions. Harry, who now lives in California, is attending the coronation without his wife or children.

Camilla's family is also front-and-center at the service, an unlikely position for her normally private children Tom Parker Bowles and Laura Lopes.

Three of Camilla's grandsons are serving as her pages, while George is serving as a page for Charles.

The coronation of Charles and Camilla marks the first time in British history that a divorced man and divorced woman have been crowned alongside each other, according to ABC News royal contributor Victoria Murphy.

Charles and Camilla are each wearing a Robe of State as they enter Westminster Abbey.

Charles’ robe was worn by his grandfather King George VI at his coronation in 1937.

Camilla’s robe was originally made for Queen Elizabeth II’s coronation in 1953.

Helping to carry Charles’ robe down the aisle at Westminster Abbey is his oldest grandson, 9-year-old George, the second in line to the throne.

"This is a really big moment for Prince George," said ABC News royal contributor Victoria Murphy. "All eyes will be on him because he is there as a future king. He’s not just there supporting his grandfather. He’s there seeing before him what, unless things change, one day he could be at the center of."

Joining George as his fellow pages of honour for Charles are Lord Oliver Cholmondeley, Master Nicholas Barclay and Master Ralph Tollemache.

Princess Anne, Charles' only sister, has joined royal family members at Westminster Abbey to watch her brother's coronation.

Anne and Charles were both alive when their mother was coronated in 1953. While Charles attended the ceremony, Anne did not because she was considered too young at the time.

Anne will play a special role in Charles' coronation, leading the procession back to Buckingham Palace following the service at Westminster Abbey.

Charles pledges the coronation oath

Charles places his hand on the Holy Bible and says, "The things which I have here before promised, I will perform and keep. So help me God."

The king signs an oath, pledging to serve the people and rule according to law.

The coronation oath marks the only time a monarch signs a written obligation to their people, according to ABC News royalty consultant Alistair Bruce.

Following the oath, Charles kneels before the High Altar and prays. Charles’ prayer is inspired by the hymn, “I vow to thee, my country.”