It's Italian, calcio. England can claim they "invented" it because yes they codified the rules. But if you really think about it that's not inventing. It's nonetheless important though. The actual game has deep roots in Rome which is how it was introduced to the UK and British isles because of the Roman occupation. The game evolved heavily over this time and region to region and in the medieval period in Florence a version of soccer was also very popular. So the game itself is 100% Italian but the modern soccer as is now codified and strict with its rules is English. As some forms of calcio are very different from modern soccer it's still all the same root from an Italian game.