The friendship between Bad Blue Boys and Gate 13 is widely regarded as one of the strongest international alliances in European ultras culture. Although no exact founding date has ever been officially recognised, the relationship is generally considered to have taken shape during the early 2010s, gradually developing through meetings at European away matches, mutual visits, and a shared ultras mentality. Over time, it evolved into one of the most respected and enduring international friendships in the European football scene.
What connects these two groups goes far beyond football. Dinamo Zagreb and Panathinaikos are clubs from the capitals of Croatia and Greece, both with rich histories and fiercely loyal fan bases. Bad Blue Boys and Gate 13 have earned a reputation for spectacular choreographies, passionate away support, impressive pyro displays and unwavering loyalty to their clubs regardless of results on the pitch. Their friendship has also been strengthened by a similar supporters' mentality, based on independence, strong group identity and a shared commitment to preserving traditional ultras culture.
The friendship is most visible through shared banners, flags, terrace visits and public displays of support. Gate 13 supporters have repeatedly displayed messages dedicated to the Bad Blue Boys, while Gate 13 banners and green-and-white Panathinaikos flags have occasionally appeared at Zagreb's Maksimir Stadium. Likewise, Bad Blue Boys symbols have been seen in Athens, underlining the mutual respect that exists between the two fan bases. Relationships like this are never built overnight—they are strengthened over years of trust, shared journeys and countless meetings on football terraces across Europe.
Travelling has always been one of the foundations of this friendship. Whenever possible, supporters from both groups attend each other's biggest matches, creating unforgettable scenes in both Zagreb and Athens. Joint gatherings before kick-off, shared chants and coordinated displays have further strengthened the connection between the two fan bases, making their relationship one of the most respected international friendships in the ultras world. The bond has also extended beyond football itself, with supporters occasionally attending basketball and futsal matches connected to their respective clubs, reflecting a friendship that reaches beyond a single sport.
However, the story of Bad Blue Boys and Gate 13 cannot be told without mentioning the tragic events of August 2023. Ahead of the UEFA Champions League qualifying match between AEK Athens and Dinamo Zagreb, a large group of Dinamo supporters travelled to Athens despite the ban on away fans. Violent clashes broke out near the AEK stadium, resulting in the death of AEK supporter Michalis Katsouris. Dozens of people were injured and more than one hundred supporters were taken into custody.
The incident attracted worldwide attention and became one of the biggest football-related stories of the year. The investigation and subsequent legal proceedings remained under close international scrutiny for months, drawing significant attention from both Croatian and Greek authorities as well as football organisations across Europe. During this period, Gate 13 supporters displayed banners expressing solidarity with the detained Dinamo supporters, including the well-known "Free BBB" message, once again demonstrating the strength of the friendship between the two groups and their willingness to stand by each other during difficult times.
While their friendship remains a symbol of loyalty and mutual respect, the tragic events in Athens also served as a reminder of the devastating consequences that football violence can have. The death of Michalis Katsouris remains one of the darkest moments in recent European football history and highlights the importance of keeping football rivalries within the boundaries of the sport.
Despite the controversies surrounding recent years, the relationship between Bad Blue Boys and Gate 13 continues to be regarded as one of the strongest international friendships in European ultras culture. Through years of travelling together, supporting one another from the terraces and maintaining deep mutual respect, the supporters of Dinamo Zagreb and Panathinaikos have created a bond that continues to be passed on to new generations.
In an ultras world where many international friendships gradually fade with time, the bond between Bad Blue Boys and Gate 13 continues to prove that loyalty, trust and shared experiences can create relationships that survive generations. Today, their friendship stands as one of the clearest examples that ultras culture is defined not only by fierce rivalries, but also by brotherhoods capable of crossing borders, languages and generations.