The intense rivalry between Celtic and Rangers is widely considered to be the fiercest in world football by many supporters not just in Scotland but from all corners of the globe.
There have been over 400 contested derbies in history between the two Glasgow giants, with just over 100 games ending in draws. Throw in multiple instances of fan clashes and vast changes to stadium ticket allocations, matches between Celtic and Rangers rarely pass without incident.
Throughout the years there have been only a handful of players who have either represented or been on the books at one point for both clubs. Even fewer have played for both in the Old Firm derby or their modern name, the 'Glasgow derby' and no player has ever transferred directly from one club to the other.
Here, GlasgowWorld profiles 15 players who have either played for or been on the books at both Celtic and Rangers in the past 40 years and how they fared at each club:
Throughout the years there have been only a handful of players who have either represented or been on the books at one point for both clubs. Even fewer have played for both in the Old Firm derby or their modern name, the 'Glasgow derby' and no player has ever transferred directly from one club to the other.