The actual words "king" and "queen" come from Old English words "cyning" meaning male ruler or king ( big help that) and "cwin" meaning queen or female ruler. ( We haven't learned a thing) Old English is a Germanic language and sounds like German to modern ears, the "C" has a hard sound, as if it were a "K."

Cyning can be traced back through earlier Germanic languages to words associated with "relationship, family, race" (kin) and "of high or noble birth." Cwen has similar roots as well as to words meaning "woman" and "wife" perhaps originally "honored wife." Cwen's roots are related to Greek word " gyné" meaning "woman", compare to today's "gynecology" medical practice specifically for women. The oricinal sense of cwen seems to be "wife", Old English specialized it to "wife of a king." later it came to also mean a woman of same noble rank as and who ruled with same authority of a king. Note that king never meant husband of a queen, that is why the husband of a ruling queen is not called a king, unless he is a king of another place, or a king for some other reason, but the wife of a ruling king is usually, but not always, a queen.

That, https://cwin.tel I think, answered the question, the following is just additional, perhaps needless and confusing information........

Other languages use other roots for their words for king and queen. Russian czar, tsar, or tzar and German kaiser are based on the Latin name Caesar, the actual family name of early Roman Emperors, assumed by others as a name and a title. The German and Slavic tribes seemed to have used Caesar to mean any Roman Empire leader in their area. The terms for Queen were feminine versions, Kaiserin, Tzarina. It might seem odd that German wouldn't use their own root word, it is due to more political reasons than linguistic ones. The German and Russian monarchies and empires were implying that they were the continuation of the Roman Empires. Actually the Caesar based words imply Emperor more than they do king, but The German and Russian Empires were not truly Empires in the sense that the Roman and later British ones were.. In modern English we usually pronounce Caesar as if it were Seezer, but in Latin the C is hard and Caesar sounds almost exactly like Kaiser or Kaysar.

Another oddity, the Romance languages based on Latin do not use Caesar as the root for king and queen. They are based on a Latin root word meaning "rule" associated with words meaning reign, regime, regulate, law, and others. In French "Roi" and Reine" (pronounced roy and sorta slurred rehen); in Spanish "Rei" and "Rena" ( ray and raynuh or raynah)

Even more off topic, you might notice a similarity between roi, rei, reine, and rena; and the given names Ray, Roy, Rene, Renee, Raymond etc but those come from completely different roots and even languages. Of course, the association with royalty may have helped their popularity. The name Regina is connected to roi and rei, but Reginald is not. The given name Caesar is common in Latin countries but not Germanic ones.

More needless information and confusion; . The Roman and British Empires usually left the k