On Saturday evening of Matchday 21, exactly 68 years to the day since the club was founded, 1. FC Köln beat Eintracht Frankfurt 3-1 at the RheinEnergieSTADION.
Watch: Köln 3-1 Eintracht Frankfurt highlights
In true Bundesliga style, the home fans in the Südtribune (the south stand) produced a spine-tingling tifo display to celebrate the birthday of one of Germany's best-known clubs.
bundesliga.com takes you behind some of the most memorable images from the Billy Goats' history on display on Saturday night…
Franz Kremer, pictured in the polaroid on the left-hand side below, was the first president of 1. FC Köln. Kremer was not only the driving force behind the club's foundation in 1948, but also played a key role in the establishment of the Bundesliga in 1963. Pictured on the right-hand side is Hennes, Köln's first Billy Goat mascot. Hennes I lived until 1966, with the eighth generation of Billy Goat currently patrolling the sidelines at home games.
History: The Bundesliga's winners down the years
During Kremer's reign as club president, the club were crowned German champions in 1962 and then again in 1964 (pictured on the left below).
Also commemorated on Saturday was one of the most famous moments not just in Köln's history, but also in European football history. After winning the inaugural Bundesliga in 1963/64, the Billy Goats qualified for the European Cup. At the quarter-final stage, Köln were drawn to play the champions of England, Liverpool FC, whom they held to a goalless draw in both the home and away legs. A decider scheduled in Rotterdam ended 2-2 and with no penalties to determine the victor, the referee was forced to reach into his wallet and toss a coin. After the coin used for first toss became stuck in the mud, a second attempt was needed. The English side "prevailed" and Köln were knocked out of the European Cup without losing a single game.
Under the guidance of Hennes Weisweiler, Köln enjoyed the most successful season in club history in in 1977/78, winning the Bundesliga title as well as lifting the DFB Cup.
Köln's success continued into the 1980s, with the club reaching the UEFA Cup final in 1985/86. It was the first time the Billy Goats had ever reached a European final, although Real Madrid CF prevailed 5-3 on aggregate.
Dictionary: Not sure you know your Abstieg from your Aufstieg?
The club's first real disappointment came more recently with relegation in 1997/98. The yo-yo years followed, with Köln relegated from the top-flight in 2002, 2004, 2006 and 2012.
As always, though, the Billy Goats eventually returned to the big time. Under the guidance of Austrian coach Peter Stöger, Köln bounced back into the Bundesliga after being crowned second-division champions in 2013/14.