Human history, even recent history, is marked by numerous mass atrocities and gross violations of what have come to be identified as basic human rights. Many of them fail to receive the attention they deserve, their memory ending up confined to the unspoken – or unheard – memories of victims and witnesses. In rare cases, however, the dreadful events transubstantiate into socially shared and emotionally charged referents, significant for extended audiences who have never directly experienced them and have no personal connections to victims or perpetrators. In short, they become cultural traumas, afforded a universal claim to remembrance, recognition, and respect. This chapter reviews the main attempts to identify the socio-cultural processes through which some horrendous events acquire the status of cultural traumas while others do not. Research shows that the transformation of collective suffering into social trauma is never determined by power alone. It is also the outcome of a complex process of signification and narration contingent upon the performative power of recognition’s proponents and adversaries. The features of such process have serious consequences – sometimes benign, sometimes paving the way for intractable conflicts – for the system of solidarities in modern societies.