The breakaway chimpanzee community wiped out during the Four-Year War was Kahama.
Kahama formed in the early 1970s when a southern faction split from the larger Kasekela community at Tanzania’s Gombe Stream. By 1974, the two groups had become separate communities, and Kasekela males began organized attacks on Kahama territory. The conflict lasted until about 1978.
The war was not a single battle but a series of raids and ambushes. Kasekela males killed Kahama males, attacked females, and absorbed some survivors. By 1977, the Kahama community had effectively disappeared, and Kasekela took over much of its former range. The conflict became one of the earliest documented examples of sustained warfare between nonhuman primate communities.
A common mix-up is confusing Kahama with Kasekela, the victorious community that Jane Goodall studied most extensively. Mitumba and Kalande were neighboring Gombe communities involved in later territorial tensions, but neither was the community destroyed in the Four-Year War.