Montecito, California - Prince Harry made a quick return to California, catching a flight within hours of his father King Charles III's coronation.

Prince Harry, who attended the ceremony alone, arrived at Los Angeles International Airport at around 7:30 PM PT to reunite with his son on his birthday.

Prince Archie turned 4 on Saturday and spent the day with his mother Meghan, the Duchess of Sussex, at their Santa Barbara home.

The Duke of Sussex's appearance at the coronation marked his first public appearance alongside the royals since he lambasted his family in his controversial memoir, Spare.

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He was seated in the third row for the crowning of Charles and stepmother Camilla in Westminster Abbey, and was placed two rows behind his brother, William.

It's understood the duke wore what he was asked to wear, which consisted of a dark morning suit and tie, his Afghanistan and Jubilee medals pinned to his suit jacket, and a Royal Victorian Order star and neck decoration.

His abrupt return to the US meant he did not appear on the Palace balcony for the finale of the day, with the Palace confirming earlier that he had no formal role at the event.