Here's a breakdown:
* Naturally Occurring Hybrids: Crossbreeding between different horse breeds has been happening for centuries, long before we had names for specific breeds.
* Known Hybrids: Some well-known hybrid horses include:
* Mule: A cross between a male donkey and a female horse
* Hinny: A cross between a male horse and a female donkey
* Zebra Hybrids: Crosses between zebras and horses or donkeys (usually with a zebra as the sire)
It's impossible to say definitively which specific cross was the "first" hybrid horse, as the history of horse breeding stretches far back. However, the earliest documented hybrid horses likely involved crosses between wild horses and domesticated horses.