William I and Henry VII both claimed their thrones in battle. The Royal Family of Monaco traces their lineage back to a couple of thugs who climbed the hill to the Monastery, killed the Monks and transformed it into their castle.
Charlemagne, at least, earned his throne at the Battle of Pointers.
>> Charlemagne, at least, earned his throne at the Battle of Pointers <<
I think it actually was his father, Charles Martel, who won at Poitiers.