Stable

A stable is any building where horses are kept. A military stable would also have a training grounds, barracks for the troopers, blacksmiths, armories, and the like. A horse must be highly trained to be successfully used in battle. Any civilization that wants to employ a large number of horsemen are highly encouraged to invest and build as many stables as possible.

General Information
Horses are raised in the stable, and horsemen develop along with the stable's level. The Stable allows Horseback Riding to be researched.

Despite what the description of the Stables says, as of July 18 2009 there is no bonus to the training time of cavalry/cataphracts for any level of Stables. The only function of higher levels of Stables is to allow higher levels of horseback riding.

A stable is required to upgrade the Relief Station. And it also increases the moving speed of your troops by 5.

Added Details
All of these times are posted before Hero bonuses. In addition, a Construction Level of 0 is used for these calculations, so the real time should hopefully be considerably lower. These are quite simply the highest possible times that you can spend on Stables.