In some of the best versions of reality, the Egyptians discover America, the industrial revolution happens early, and robots take over. In others, the Renaissance produces a plutocracy which leads to a utopia(or perhaps to anarchy).  It’s all in the subtle details. As a time traveler, you’ve seen it all. What’s important is who’s in control when time travel is invented. Other time travelers are mucking with things for their own reasons.  Your course is clear: you will tamper with history as much as is needed.  You will step on however many butterflies it takes.  The goal: to get a perfect world, under your own benign rule.