The Battle of Eley

Leofrich the Deacon understood this to be a spell that was cast by the woman to defeat the rebels. But I suspect that whether or not that spell actually had any magic behind it probably didn't matter. Just having an old lady telling you off like she was your mom and then dropping trow was probably more than enough to weird out the English. And we're told she actually did this three times, which is a lot in certain magical circles.