The First Horse Riders, Horse Domestication on the Eurasian Steppe

Who were the first horse riders in history We know about horse domestication but knowing who were the first horsemen is more difficult. The idea of the Yamnaya Bronze Age horse warrior riding down a fleeing Neolithic farmer is a powerful image but is it true Were the people of the Botai culture the first horsemen Was it those of the Sredny Stog or perhaps the Khvalynsk culture Or was it even the people of Bronze Age Mesopotamia