I'm trying to find out if and how Baldwin II and Baldwin IV, kings of Jerusalem, are related.
Their wikipedia pages don't make it easy to determine this.
So, my question is whether these Baldwins, by virtue of their name and suffix, have to be related?
In other words, can I assume they are at least somewhat closely related?
Who or what determines if a person can become the next person in line to carry a name (with an incremented suffix)?