Abstract: A surprising amount of violence is committed in the name of  "honour". Honour violence takes many forms, from so-called "honour killings", to bar-room fights, to blood feuds. Norms of honour demands a great deal, but seem to provide very little. If so, the puzzle is how and why these seemingly pointless and destructive norms are so widespread and stable across many cultures and throughout history. In this paper, we argue that honour norms are best understood as a species of social norms that solve problems related to deterrence and assurance that arise in societies with weak or failed governance institutions. Seeing honour in this new way is both explanatorily powerful and it opens up new possibilities for understanding and, possibly, changing destructive honour norms. Our hypothesis also has implications for recent debates about whether honour norms are a species of moral norm, and whether this poses a threat to moral realism.