Buddha's past lives in the Jatakas

In multiple Jataka stories, the Buddha tells of his different past lives, multiple of which occurred under King Brahmadatta. Am I missing something here? How is it that the Buddha was living multiple past lives, all during the lifetime of one king? for example : http://www.sacred-texts.com/bud/j1/j1010.htm http://www.sacred-texts.com/bud/j1/j1008.htm