Prince Charles was once called the "hardest-working member of the Royal family," but the heir to the British throne does find time to engage in a few leisurely hobbies. Despite being considered only an amateur, the Prince of Wales has made about $7.75 million selling prints of his watercolor paintings at his country estate and at art galleries in England, according to Artnet.

The royal figure has a long history with the arts. He began painting in the '70s and '80s when he was a student at Gordonstoun, a school in Scotland. He would go on to discuss art with artists like Edward Seago and Bryan Organ, and later to co-found The Prince's Drawing School.

Today, his individual prints sell for up to $21,668 with the stipulation that all of the proceeds go to The Prince of Wales's Charitable Foundation. However, the self-described "enthusiastic amateur" never sells the original works. More than 100 of his paintings, many of which depict landscapes from his travels and from the family's estates, can be found in an online gallery on Prince Charles's official website.

"The Prince likes to paint whenever his schedule allows—whether on private holidays, or during a spare moment on an overseas tour—and finds it a most absorbing occupation," according to the website.

[h/t Artnet News]