The tree saddle was a late development.
The first horses were ridden bareback.
Quickly cloth and simple seat padding were adopted.
A few centuries after people learned to ride horses, nomads from the steppes of central Asia had developed a rudimentary saddle.
Because of the better weight distribution that it offered, it made long distance riding more comfortable for both horse and rider.
It was not until about 200 BCE that the 'tree saddle' was perfected, which consists of a wooden frame with padding, pommel in front and cantle in the rear.
Because of the addition of a high cantle it is sometimes called a 'cantled saddle'.
The saddle helps the rider to fight hand-to-hand from horseback, however in melee or archery stirrups are more important.
A saddle, if equipped with a good cantle, is better in helping the rider absorb the shock of a heavy cavalry charge with a spear or couched lance, either his own or that of his opponent.
But evidence points out that saddle is but a secondary factor in shock combat.
The weight, strength and horsemanship of the rider are the most important factors in this matter.
In the knightly era other tools were developed to supplement the saddle.
Lance rests (better named 'lance stoppers') are flanges attached to the armor of the rider, that help keep the lance from shifting backwards on impact at a charge.
Specialized lances are more elaborate than simple spears; they have vamplates: small circular plates behind the grip to prevent the lance from slipping from the hand.
Spurs, an older invention, are pricks or rowels attached to the boots of the rider, to use in commanding the horse.
All these, combined with the often overrated stirrups, allowed the Medieval European knights,
who specialized in the charge on horseback with couched lance, to rule supreme on the battlefield for a time.
More modern saddles often dispense with the wooden tree.
They are lower and almost exclusively made of leather.
These are more comfortable for riding, but offer less stability.
They started to replace the high saddles when firearms were introduced and horses saw less and less use as solid hand combat fighting platforms.
War Matrix - Tree saddle
Greek Era 330 BCE - 200 BCE, Weapons and technology