Dr Jane Goodall first began studying the chimpanzees of Gombe, Tanzania in 1960. Her pioneering work forever changed the way we understand the species - and her project has become the longest-running continuous field study of primates ever conducted. But until now, documentaries about the chimps of Gombe have focused largely on the males.Matriarch focuses entirely on the stories of the females of Gombe for the first time. Produced in collaboration with Dr Goodall, and featuring revealing interviews with her and a team of scientists and field assistants, the series focuses on Gremlin, the alpha female of the Kasekela troop. At 54, she is the oldest chimpanzee mother ever recorded at Gombe - and she's held her alpha position for nine years through a careful combination of intelligence, patience and strategic relationships. But competing females are waiting in the wings - for when Gremlin's strength begins to wane. The normal rules of chimpanzee society may see power pass to an influential female from a rival family, but Gremlin has forged deep and caring bonds with her many daughters – creating a rare female alliance. Can they keep hold of the privileged top spot?