All kinds of evidence has been uncovered that organized soccer was being played in Scotland as early as the 15th century.
He discovered a manuscript of accounts from King James IV of Scotland that showed he paid two shillings for a bag of ‘fut ballis’ on 11 April, 1497. More evidence came with we came across several diary accounts of football being played in places like Stirling Castle, Edzell Castle and Carlisle Castle. The games were played on pitches smaller than the current regular football field, and featured between 10 and 20 men on each side.
Maybe we can get that guy who wrote the epic Reddit thread about how a 2000-man Marine unit might fare against the circa-23 B.C. Roman Empire (and got a movie deal for it) to write a scenario in which Messi, Ronaldo, Rooney, Iniesta, et al travel back to Scotland in the 1500s to take on the King and his footballers. (via @tomfossy)