Complex social life has been proposed as one of the driving forces for the evolution of cognition. Aside a large group size and a high degree of fission-fusion dynamics, the formation and use of valuable relationships (social bonds) have been discussed as the main factors constituting social complexity in mammals. Yet it is debated, if this is also true for birds. Reporting on recent data from captive and wild ravens Corvus corax, I argue that i) the quality of social relationships of these birds is comparable to that of primates and ii) that the relationship quality between individuals explains various patterns of their advanced conflict management (coalition formation, intervention in fights, post-conflict reconciliation and bystander-affiliation). In addition, I argue that iii) social bonds may be advantageous during foraging but iv) that they may come with the costs of increased aggression by third parties. These findings support the idea that the need for, and use of, bonding partners outside reproduction may be one of the factors driving the cognitive evolution in these large-brained birds.