Diocletian and the Age of Constantine

Diocletian was a victim of his own success, writes Julian Zelizer. He wanted the whole empire to be his from the very beginning, but he can and did tinker around with the means he used to achieve that end all the time. But once that elder generation had been cleared out, there was nothing left to check constantine's ambitions. After diocletian died, constantine appears to have looked into his own heart, then sized up the com titian, and then decided that the time had come for caution to give way to daring. Because, after all, fortune favors the bold.