There've been many wars in which the side known as the "North" conquered the one known as the "South", e.g.:
- Three Kingdoms period in China: the Northern kingdom conquered the two Southern ones
- The Northern & Southern dynasties period in China also ended with a Northern dynasty conquering the South
- Vietnam War: North Vietnam conquered South Vietnam
- American Civil War: the Union ("North") conquered the Confederacy ("South")
- Korean War: Stalemate
I'm curiously unable to think of a war which ended in a Southern victory. Has there been such a war?
To clarify: I'm most interested for North vs. South wars here. An event such as Germany's conquest of Norway in WW2, although it is a case of a Southern invader conquering a Northern country, isn't actually a North vs. South war, because it's multi-front (there was also an Eastern front, a Western front, etc).