From the end of the nineteenth century to the mid-twentieth century, gangs and secret societies (banghui) exercised enormous influence on Chinese society and politics. The two portrayals of banghui in historiography – as modern criminal syndicates that came out of an emerging capitalist economy or, alternatively, a cultural succession of traditional secret society – are so distinct that their proponents often speak past each other. Revisiting primary and secondary materials on the Shanghai Green Gang, one of the most active banghui organizations during the Republican era (1911–49), this article aims to bridge the two understandings by focusing on the gang’s self-legitimation claims. Facing rapid social changes of the early twentieth century, I argue, the Green Gang reframed its use of violence as disciplinary, revolutionary, and nationalistic to gain public legitimation. Together with its involvement in state building and resource extraction, the gang’s cultural work contributed to its prominence and led multiple political authorities to promote it to an exceptional degree.