With a PoD no earlier than 1300, advance the entire humanity's scientific, technological and industrial (these three are linked) capacity by one century.
And by 1850, the humanity must reach OTL's 1950 level in terms of science, technology and industry*.
*I mean generally.
**In my opinion, the type of war most helpful for scientific advances are cold wars. Remember how Russo-American Space race helped scientific progress?