Exactly 30 years ago, a coalition of Cambodian and Vietnamese troops forced Pol Pot and his followers from power - after a four-year reign which left as many as two million people dead.
But Victory Day is not universally celebrated in Cambodia.
Even in 1979 it was a strange kind of victory. There was no hero's welcome for the conquering troops. But nor was there a nervous population, fearful about the intentions of the incoming army. Because Phnom Penh was almost completely deserted.