Prince

A prince was a royal title referring to the son of a monarch.

On Earth in the 20th and 21st centuries, Charles, the son of Queen Elizabeth II, was titled Prince of Wales. 

In the 23rd century, Raviki was a prince of Nukolee, the son of Djan and his wife. 

In the 24th century, Si Cwan was a prince of the Thallonian Empire until its fall in 2373.