On 15 November 1913, Denmark's Nils Middelboe became the first non-British player to make an appearance for Chelsea.
It wasn't the first "first" for Middelboe, who scored Denmark's first-ever goal in the opening match of the 1908 Summer Olympics. He helped Denmark to the silver medal that year, then again in 1912. By the latter, he had become the captain of the national team.
In 1913, he moved to Chelsea from Kjøbenhavns Boldklub, where he had spent the previous ten years. Reportedly, he originally intended to sign with Newcastle, but switched to Chelsea at the last minute. Upon arriving at Stamford Bridge, he received the captain's armband and led the team to a 2-1 victory over Derby County in his first match.
While at Chelsea, he maintained his amateur status, keeping another job at a London bank. In order to accommodate his other career, Chelsea did not require him to travel for away matches.
Middelboe remained with Chelsea for ten years (but only five seasons, thanks to the suspension of league play for World War I) and made a total of 46 appearances in all competitions. Afterward, he played for a couple of amateur sides, then became a director of Clapham Orient in 1929. In 1936, he returned to Denmark as coach of Kjøbenhavns Boldklub.