Thus, most cavalry types of the Hellenistic armies can be considered heavy, regardless of their armor, as long as they are equipped with lances and act in dense formations. Traditional Greek cavalry was usually employed to cover a retreat or pursue a retreating enemy. A cavalry engagement usually involved a lengthy exchange of javelins; close combat was avoided. The Macedonian Hetairoi (Companions; Companion Cavalry) may have been the first true, able shock cavalry, armed with long lances and heavy armor. Their tradition was carried on in the Hellenistic times and troops similarly armed were called doratophoroi or xystophoroi (both terms translated as lance bearers or plainly lancers). The term Hetairoi was reserved for units comprising men of aristocratic blood. These doratophoroi were primarily used against enemy cavalry; their use against densely deployed infantry was very limited. Their extreme version were the cataphracts of the Seleucid cavalry. The various Agemata (pl. of Agema), usually the elite bodyguards of the Hellenistic Kings, were similarly armed.