need help finding fantasy book series

I am trying to find the name of a fantasy book series I read many years ago. It has a grandfather wizard who lives in a tower. His grandson who is also a wizard who becomes a king and his sister who is also magic. These characters often change into wolves. It even tells of how the wolf pack works. The world is overseen by a group of gods that are all related. I hope that's enough because I am having a hard time putting the idea from my mind into words on the page. Thank you in advance to anyone that can help and those that try