| "Prince consort" is a title for a man who is married to a queen regnant, but since his wife is the monarch and actual ruler, his title is not king, but "prince consort". Presumably designed to keep men who married queens from acting as king of countries they had no claim to rule. Gritchka tells me that the title was created for Queen Victoria's husband Prince Albert, and that previous consorts of English queens either were called king (for example, Mary I and her husband Philip II of Spain where Philip's subordinate status was specifically stated in the marriage treaty, or William and Mary who were offered the crown of England jointly even though Mary was first in line to it and William was third in line) or weren't actually called prince consort (Queen Anne's Prince George of Denmark).
Prince Philip of England is an example of a prince consort, since he is married to Queen Elizabeth II, who inherited the throne. (This is not an official title; Philip received the rank of Duke when he married then-Princess Elizabeth and did not become an official Prince until some time after his wife became queen.) | 
