The Congo-Ubangi watershed in the northern margins of the Congo rainforest is home to a complex mosaic of genealogically and structurally diverse languages spoken by small-size communities with different material cultures and subsistence specializations. Straddling the borders of three modern countries in Central Africa, i.e., Congo-Kinshasa, Congo-Brazzaville, and the Central African Republic, it is a major hotbed of linguistic, cultural, and genetic diversity with a deep history of human occupation. Despite the myriad of insights it could generate about language evolution and deep human past, it is poorly known due to difficulty of access and an astonishingly intricate configuration. CONGUBANGI will realize a breakthrough in our understanding of how linguistic diversity correlates with cultural and genetic diversity and why it originated and persisted in this specific ecoregion for millennia through an interdisciplinary approach involving linguistics, archaeology, and genetics. Understanding the genesis of a central area in the continent where mankind originated represents a unique opportunity to learn about our shared human history of evolution, migration, and diversification, and their impact on human language, a faculty unique among all forms of animal communication. Beyond research, CONGUBANGI will replicate world-wide efforts to preserve local linguistic diversity in a region where it is threatened to extinction by multiple uniformizing pressures, so that it can be made permanently available for posterity.