While the time of the development of saddles and stirrups is difficult to pin down, art and other more permanent depictions of the two suggest that they may have been seen together somewhat commonly starting in the early 500’s B.C. The idea for each piece may have existed hundreds of years earlier, but the idea became readily available to most cultures starting in this era.
image courtesy of: http://pixabay.com/en/horse-western-saddle-pomel-horn-176990/
It is difficult to describe the importance of horsemanship in early warfare without specifically addressing the advantages gained by particular civilizations because of their use of horses in their armies. However, there is a useful comparison to make which illustrates how stirrups and saddles provided advantages to early horsemen.
Riding a horse in itself could provide some advantage to a warrior because arriving on the field of battle, he would be less exhausted from the journey.With a good saddle, it is easier to stay on a horse, which provides an even greater advantage in this respect.
Another aspect of advantage occurs after a battle or during a tactical part of a battle. Horses allow for quicker movement on the field, so a group of riders could take advantage of a tactical situation which allowed them to divide and confuse the enemy (much like Alexander the Great).
Stirrups provide a greater advantage during the battle; they allow warriors on horseback to put more power into the strokes of their weapons, or to rely on the speed and weight of their horses to drive a spear or lance further into a crowd of enemies. The critical advantage provided is that it is much more difficult to unhorse a rider who has stirrups.