Dr. Jane's once peaceful-seeming chimpanzees were heavily engaged in what amounted to a sort of primitive warfare during the years of 1974-1977. It had begun when the chimpanzee community began to divide. Seven adult males and three mothers and their offspring began spending longer and longer periods of time in the southern part of the range over which the whole community roamed. By 1972, it was obvious that these chimpanzees had formed an entirely new and separate community, which became known as Kahama. When males of the two communities encountered one another in the overlapping zone between the two, they threatened one another in a typical territorial behavior. However, a series of deadly brutal attacks perpetrated by the powerful Kasekela community on individuals of the Kahama community followed. It was known as the Four-Year War at Gombe.
The Four-Year War of the Gombe chimpanzees could not, of course, measure up to human warfare
of this sort, yet it had become clear that the apes were on the very threshold of this otherwise uniquely human achievement.
After all, in human history the large-scale deployments of men and weapons did not emerge, fully fledged, overnight. Like all
our cultural achievements, war evolved gradually over the centuries from primitive chimp-like aggression to the organized
armed conflict of today. There are still living groups of indigenous peoples whose form of warfare is not so different from
that of the Four-Year War of the Gombe chimpanzees-where the raiding parties creep into the territory of the next village to
kill and plunder.