Football wasn't spread (just) through conquest.

The UK never conquered Argentina or Brazil yet if you'd look at football fans in both countries you'd think Argentina or Brazil not only invented football itself, but they also built an entire cult around it :-p

Football/soccer is a British import likely 'invented' somewhere else

A quick look says that Wikipedia disagrees with you. It's homegrown.

If you claim otherwise (and claim that Wikipedia is an inadequate source), that's fine, but show your evidence.

What Wikipedia article are you looking at? Even the article on 'Association Football' which I assume is referring to the modern organized form of the sport that did develop in the UK has a long history section referring to the many origins of 'football' or 'soccer'.

From the Association Football article:

"Association football in itself does not have a classical history.[26] Notwithstanding any similarities to other ball games played around the world, FIFA has described that no historical connection exists with any game played in antiquity outside Europe.[3] The history of football in England dates back to at least the eighth century.[33] The modern rules of association football are based on the mid-19th century efforts to standardise the widely varying forms of football played in the public schools of England."

So, yeah. There are similar games. But the game in England is not an import.

How do you know?

HN guidelines frown upon using non-canonical links. Please don't do that.

The above link resolves to this, so folks don't have to indulge in the click-tracking:

https://www.google.com/search?q=who+invented+soccer

The UK's relationship to Argentina was not conquest, true. But it was as close to colonial as you can get without stepping over the line.

There's a school called St. Andrews in Buenos Aires. If you know, you know.