Wiktionary
born to the purple
a. born and raised in a royal family.
Wikipedia
Born to the Purple
"Born to the Purple" is an episode from the first season of the science-fiction television series Babylon 5. This episode is named after the Greek word porphyrogennetos, referring to special birthright or privileged heritage, royal birth.
Usage examples of "born to the purple".
I tell you that those Jovians, whatever they are, are born to the purple.
He could wear sack cloth and ashes and still be more a prince than most men born to the purple and dressed in the richest raiment and most costly jewels.