The literature on the relationship between leader behaviours and effectiveness is a jungle of complementary yet often conflicting leadership theories that perplexes researchers and practitioners alike, as indicated by various theories of bright and dark side leadership (i.e., leader behaviours reflecting widely considered positive and negative leadership qualities, respectively). We disentangle this jungle by offering a conceptual model that improves our understanding of bright and dark side leadership and their respective effectiveness, based on the concepts of leader character and context integrity. Our theory helps to reconcile the various bright and dark side leadership theories at a general level and suggests critical implications for leadership theory and practice.