Horses do not have territories, they roam over vast expanses of land as they are nomadic. Horses do have a personal space that extends around themselves and if invaded will defend their space if need be.
they rear and buck the other horses, so keep your distence when near horses fighting because you might get hurt. the back legs can hurt you but the front legs can kill you
no
Horses are a flight animal, they will run away from danger.
with a fence
They will bark at them to try and defend there territory, they are saying to them "this is my territory"
No. They simply establish dominant horses in herds.
Its kind of like a mark of territory
it pees on one another
it shoots ink at its rival to intimidate it.
yes
a way to defend them selfs
The horses territory is a place where it's lives it can be of any size and the horses guard or protrol the area. In a horse world the best stallions get the best area and also get the best mares.