What are these cultures which existed solely on vegan diets? Honest question, I searched but couldn't find the answer, there was a response on Quora which mentioned some Buddhists are vegan by default, and some Hindus and Essene Christians are vegetarian, but she "wasn't aware of any 100% vegan cultures."

I can understand vegetarian cultures surviving, since they can acquire essential nutrients through the animal products found in diary, but would be intrigued to find a vegan (plant-based only) culture. Was there perhaps one in the distant past or ?