Tara bandu is a traditional ceremony in Timor-Leste that enshrines a customary law with official recognition since independence, which generally applies to the spatial scale of the smallest administrative division of the territory (suco) and several years of timespan, rooting in tradition (lisan), concerning natural resources management and also relations among people. There is evidence related to the concepts of adat (tradition in Indonesia) and pemali (taboo) in Southeast Asia and Austranesia, suggesting that precursors of tara bandu should exist before the Portuguese arrival in the early XVI century. Yet, there was a subsequent diachronic process of hybridization of static iconic devices and other traditional Timorese practices with the vocalized Portuguese colonial bandos, evolving to a choreographic complex ritual with several semiotic dimensions: the sacrificial animist performance addressed to the ancestor’s spirits and a supernatural environment (lulik), dances and others including Catholic rites, then focusing on written documents endorsing commitments. Contemporaneously, tara bandu is a salient event anchoring communities in defining participatory land use plans including agreements on property boundaries, rules of engagement and also interdictions and sanctions. Tara bandu is mentioned nowadays as an example and case-study of bottom-up strategies for environmental peacebuilding processes.