It is a recurring theme in fiction that a knowledgeable person scares off some ignorant by pretending that the solar eclipse is caused by the wrath of gods, or similar. For example, see the Pharaoh by Prus. [MetaQuestion: What is the first literary work where this happens?]
Did such a thing ever happen in real?
Here I mean some historical event, and not just your neighbors scaring their kids.
The only event I am aware of where the eclipse allegedly changed history is the Battle of the Eclipse, though this is debated, and also would not be an example where one side would have used it to their advantage by knowing about it beforehand.
For predictions of eclipses, see this other question on this site.