A prince du sang is a person legitimately descended in male line from a sovereign, the female equivalent of princess of the blood being applied to the daughter of a prince of the blood. The most prominent examples include members of the French royal line, but the term prince of the blood has been used in other families more generally, for example among the British royal family and when referring to the Shinnōke.
In some European kingdoms, especially France, this appellation was a specific rank in its own right, of a more restricted use than other titles.