The word "chariot" comes from the Latin term carrus, a loanword from Gaulish. A chariot of war or one used in military parades was called a car. In ancient Rome and some other ancient Mediterranean civilizations, a biga required two horses, a triga three, and a quadriga four.
The horse chariot was a fast, light, open, two-wheeled conveyance drawn by two or more horses that were hitched side by side, and was little more than a floor with a waist-high guard at the front and sides. It was initially used for ancient warfare during the Bronze and Iron Ages; but, after its military capabilities had been superseded by cavalry, as horses were gradually bred to be bigger, the chariot was used for travel, in processions, for games, and in races.
The critical invention that allowed the construction of light, horse-drawn chariots was the spoked wheel. The earliest spoke-wheeled chariots date to ca. 2000 BC. The use of chariots peaked around 1300 BC (see Battle of Kadesh). Chariots had lost their military importance by the 1st century AD, but chariot races continued to be popular in Constantinople until the 6th century.
Horses were introduced to Transcaucasia at the time of the Kura-Araxes culture, beginning about 3300 BC. (Archeologists have not found earlier horse bones in the area.) During the Kura-Araxes period, horses seem to become quite widespread, with signs of domestication.
The domestication of the horse was an important step toward civilization. An increasing amount of evidence supports the hypothesis, that horses were domesticated in the Eurasian Steppes (Dereivka in Ukraine) approximately 4000-3500 BC.