Enrique el Joven
Before primogeniture was enshrined in European law and tradition, kings would often secure the succession by having their successor (usually their eldest son) crowned during their own lifetime, so for a time there would be two kings in coregency—a senior king and a junior king. Examples were Henry the Young King of England and the early Direct Capetians in France. Sometimes, however, primogeniture can operate through the female line.