Amber: The Next Generation
King Oberon has spent some time and effort making it difficult for any of his children to have an obvious claim, over and above the others. However, there are some facts.
Then, without divorcing, he had Eric, born to Faiella. He then dissolved the marriage to Cymnea ‘ab initio’. From the beginning. This left the oldest three with very uncertain status.
Around this time, he probably fathered Caine out in shadow.
He married Clarissa and had Bleys and Fiona. Then, outside that marriage, he had Llewella, born to a noblewoman of a place called Rebma. A reconciliation with Clarissa resulted in Brand. Llewella is a recognised Princess.
This is of course just the official list, and even that has several big questions over it.