The most famous body of somatophylakes were those of Philip of Macedon and Alexander the Great. They consisted of seven men, drawn from the Macedonian nobility, who also acted as high-ranking military officers, holding command positions such as general or chiliarch. Alexander the Great appointed Peucestas as eighth somatophylax after the siege of Malli.
Arrian tells us he was son of Orontes, a descendant of the independent princes of the Macedonian province of Orestis. As the commander of a battalion of heavy phalanx infantry, Perdiccas distinguished himself during the conquest of Thebes (335 BC), where he was severely wounded. Subsequently he held an important command in the Indian campaigns of Alexander. When Hephaestion unexpectedly died in 324 BC, he was appointed his successor as commander of the Companion cavalry and chiliarch.