Prince William's Coat of Arms Honors Diana

L O N D O N, July 10 -- British royals mark their coming of age a bit differently than the rest of the world.

Rather than showing off a driver’s license as proof of maturity and almost all-grown-up status, a royal displays a coat of arms.

And when the coat of arms of 18-year-old Prince William was unveiled Sunday, the son of the late Princess Diana made his first mark on the traditions of the royal family.

The Prince asked that a small, red scallop shell be incorporated into the design of his personal coat of arms. The shell has been a motif in the coats of arms of Diana’s ancestors, the Earls Spencer, since the 16th century, and was used by Diana in her own coat of arms.

Every member of the royal family gets to choose a way to personalize the royal arms a little bit. It’s called a “mark of difference.”

But William’s little shell is a big deal. Traditionally, the chosen mark of difference is derived from the symbols of the father’s side of the family, not the mother’s.

“It is a welcome innovation to incorporate maternal symbols into the royal family’s arms and it is something that Prince William and his family wanted to do,” said Peter Gwynne-Jones, who is responsible for royal heraldry. “In the fullness of time, Prince William’s arms will change, as the Prince of Wales’s shall, but a precedent has been set here that others in the royal family may well follow.”

The shell design appears four times in the coat of arms for the future king, wherever the “label” appears: on the shield, on the necks of the lion and the unicorn supporting the shield, and on the neck of the small lion device above the shield.

As heir to the heir of the throne, William’s label has three points. Other grandchildren of the monarch have labels with five points.

Prince William’s arms also incorporate aspects of the royal arms used by his grandmother, Queen Elizabeth II, and those of his father, Prince Charles. Both Charles and the Queen have approved William’s coat of arms, and a royal license is being drawn up to officially grant it to the Prince.