Red Star Belgrade and Olympiacos might not scream brotherhood for most neutrals across Europe, but their 30-year 'brotherhood' was on full display on Tuesday when both sides met in the Champions League group stages.
It's a relationship which Agona Sport claim started between ultra groups Gate 7 (Olympiacos) and Delije (Red Star) in the mid-1980s.
Although there wasn't any one thing which caused the two clubs to form such a close bond, both Serbia and Greece have a predominantly Christian Orthodox faith, while the clubs also play in similar red-and-white kits.