Originally Posted by CyrilVladisla
Was it necessary that Valdemar I had to gain church approval for hereditary rule by his dynasty?
Eeh, what do you mean?
Until 1660 all Danish kings were elected (really acknowledged) at the local councils all over the realm, and one of the first things they did when they got a son was to ensure he was acknowledged as the heir.
That ensured stability and prevented another pretender from making a claim. After all Valdemar I came to power after a civil war.