The Buddhist teacher Nichiren (1222-1282) has tended to be marginalized by many scholars of Buddhism as “intolerant” for his exclusivistic claim that only the Lotus Sutra leads to salvation in the Final Dharma age (mappo). While the Nichiren Buddhist tradition has often been aggressive in asserting its exclusive truth claim and in opposing other forms of Buddhism, the label of “intolerance” does little to illuminate how this exclusivistic stance has functioned within the history of the tradition both as a unifying force and a strategy of legitimation. This brief historical overview first outlines the origins of “Lotus exclusivism ” in Nichiren’s thought. It then goes on to discusses how this claim to represent the only true Buddha Dharma enabled early Nichiren communities to define and perpetuate themselves vis-a-vis more powerful institutions, and it shows how it has been repeatedly refigured from medieval times to the present in response to changing circumstances. The article also explores the issue of ongoing' conflict within Nichiren Buddhism over whether, and to what extent, confrontation with other Buddhist traditions should be pursued.