What was the name of Alexander's personal bodyguard unit?

Alexander's personal bodyguard unit was called the Somatophylakes. The Greek term means “bodyguards,” and it referred especially to an elite group of Macedonian nobles who protected the king and served as senior officers.

Under Alexander, the Somatophylakes usually numbered seven men. Their responsibilities went far beyond ceremonial protection: members commanded troops, led assaults, governed territories, and advised the king. Alexander appointed Peucestas as an eighth bodyguard after Peucestas saved him during the Mallian campaign in 325–324 BCE.

The Somatophylakes are sometimes confused with the Hetairoi, or Companion Cavalry, and the Hypaspists. Those were important military formations, but neither name specifically identifies Alexander's personal bodyguard council. The term could also be used more broadly for royal bodyguards, so context matters. The famous “Seven Bodyguards” were a select group within Alexander's wider military and court structure.