I believe the question implied "in living memory". Popes notoriously don't directly speak up even against atrocities such as genocides, let alone act on it (with levers that are most certainly in their control, such as excommunications).
Pope John Paul II was a crucial figure in the fall of communism in Poland, even though he never opposed the state directly - just the fact that he was Polish and that the state couldn't censor his speeches and visits and demonstrated to the deeply religious nation that there is a path outside of the the one dictated by the state that is credited with a significant contribution to the forces that eventually led to the events of 1989.