US Civil War - North beats the South
Vietnam War - North eventually overruns the South
Korean War - Tie, only because of the continual presence of a US garison on the DMZ.
War in Afghanistan - Northern Alliance defeats Taliban (with USA on the assist)
Happy coincidence or something more sinister?
Some sort of conspiracy of cartographers?
WW1/WW2 - USA is south of Germany. (But Britain is north, so who won the war?)
1776 - USA south of Britain
1066 - France south of Britain (favor returned at Agincourt)
Afghanistan (different war) defeats (or fails to be conquered by) Russia.
Small, selected samples can be used to show anything.
It’s because the northerners are fighting downhill. 
I think that it’s interesting to note that the Chinese character for “north” originally meant “defeat” and comes from a pictogram of someone turning his back to the enemy. It’s still used in that sense today in the compound word baibei, “defeat”. I.e. to go north means to run away in defeat.
The northern enemies in question were Mongol tribes, and even though Gengis Khan did conquer China, the Chinese had been (more or less) successfully holding off the Mongols for over 1500 years.
Then, of course there’s the case of the Roman empire.
Rome vs. Carthage -> Northern victory.
Rome vs. Celts -> Southern victory.
I think Rome defeated, and was defeated at one point or another by enemies coming from all four directions.
You should perhaps consider the fact that when you’re Russia, North America, Great-Britain, or Mongolia, the odds of going to war with a northern enemy are, well, pretty slim.
I can see the headline: Santa Claus surrenders in war with Iceland.
STOP GIVING CANADA IDEAS.
North Yemen didn’t defeat South Yemen.
Can’t go wrong with a good Tom Stoppard joke!
There might be some small kernel of truth to this. Taking Russia as an example, its historical defense policy has often been to retreat until winter arrives and the snow stops the enemy. Thus the north often has the advantage of a natural defense that the south may not enjoy. It certainly helped against Napolean when he tried to march to Moscow.
Note that Russia had a completely different offense strategy when fighting the Winter War against Finland. To wit, troops were equipped with trucks that couldn’t move through the snow, while the Finns attacked with infantry on skis.
In the end, the USSR got the better of Finland – which, being mainly north of Russia, is another counterexample.
Perhaps the “North” rule only works for internal wars (as in all four examples given in the OP).
But the USSR failed in its objectives regarding Finland, so couldn’t we count that as a win.
Events at the dawn of history augured better for southerners. Southern Egypt conquered Northern Egypt.Egypt cite (Upper, meaning upriver, hence southern Egypt).
Too late. Our battleships are on the way. (By battleship I of course mean two guys in a canoe with a slingshot.)
What about The Great Northern War? Sweden defeated Russia’s allies Denmark and Poland (bouth south of Sweden) fairly quickly, almost defeated Russia in the beginning, but pushed further and further into Russia (the Ukraine, and eventually Turkey) and they were eventually defeated in a glorious battle commanded by Peter the Great, allowing Russia to conquer much of the Swedish Empire.
Yes, Sweden did once have an empire.
It’s because the heat makes people lazy… northerners are just tougher.
The Great Northern War. That was a good war. Good war.
I just knew Bob & Doug McKenzie were still around.
Tripler
You hoseheads.
Look out, South Dakota.
Libertarian, have you forgotten the 1994 civil war in Yemen so soon? O Yemen expert. The rebels in the South got a smackdown from the federal government in the North. A guy from Yemen I work with and his whole family had to leave the country because there were shells falling near their house ‘n’ shit. Even though they were from the North (Ta‘izz), they thought it would be safer to get out of Dodge.
P.S. Then there was the “Reconquista.” However, that was a reaction to the previous victory coming up from the South. The tides of fortune can turn either way.
The Vikings travelled south striking terror in Europe.
And in the western Pacific the Haida paddled south to strike terror in the Pacific Northwest.
And in the eastern Pacific, a few years later the Japanese sailed south to strike terror in Korea, Phillipines, and Indochina.