Just like the way there have been multiple Kage's over the centuries (in the Naruto-verse), have there also been yonko's for previous generations? What i'm trying to grasp is if the Yonko title started with the "Big 4" (Whitebeard, Kaido, Big Mom, shanks). If that were the case then Shanks would have been the youngest,and most likely the newest addition at that time.
Or Did Shanks replace a previous Yonko just like how
Blackbeard replaced Whitebeard?