Latin American international lawyers are prolific historians. However, while having profusely written histories of international law, Latin Americans have shied away from historiographic controversy. Latin Americans have not disagreed much about how to conceive and write history, but they have had sound disagreements about the international law that is constructed by history, they have disagreed over different ways of using history as law. This chapter offers a history of these disagreements. Some Latin-Americans have used universal histories, echoing the familiar Eurocentric history from the Latin-American periphery to the core, in order to gain doctrinal authority to speak and change international law. With a similar goal in mind, other Latin-Americans have used particularistic histories, foregrounding the region’s doctrinal divergences and contributions to universal international law. Universalist and particularistic histories were dominant between the first half of the nineteenth century and the second half of the twentieth century, between independence and the Cold War. Towards the end of the Cold War, these two types of history merged into one, presenting the region’s historical trajectory as in harmony with universal international law. This represents a break. If in the nineteenth century an international legal tradition emerged in Latin-America, during the twentieth century it radicalised, diverging from international law as conceived from the West. From the Cold War merger an endemic history emerged, which depoliticised and deradicalised the Latin American tradition. Exploring this history of history-writing in the region may help rearticulating a more ambitious Latin American international law.