10mm Successor Companion Cavalry. The "Companions" were the elite cavalry of the Macedonian army from the time of king Philip II of Macedon and reached the height of their prestige under Alexander the Great.
I use these figures as heavy cavalry for Command and Colors Ancients. They are best employed to punch holes and divide up the enemy lines. Be careful however, as you must provide room for them to retreat or they can be destroyed if caught.
These figures are by Magister Militum and are from their Ancient Successor range.