A general name for the royal guards formations?

[Michael J. Taylor]

The terminology varied widely in the Hellenistic world, but περὶ τὴν αὐλήν, "of the court" was sometimes used as a signifier of what we might call a royal guard, although off the top of my head Polybius only uses it for cavalry. The most routinely privileged units in the Hellenistic world were the agema, a subset of both peltasts and cavalry who also enjoyed a special connection with the king.