How come horses were so common all over the world in the past

Question

I recently watched a documentary about a brief history of each continent when I noticed horses were really common everywhere for an example Genghis khan in Asia, Saladin in Africa, natives in North and South America and all over Europe too. I know they’ve been brought with settlers to Australia because it was mentioned in the documentary but what about the other continents ?

In: 756

Answer 1

Horse provided mutal relationship with us. We provided for them and they let us use them for transportation and work. Most effective mode for many years.