Equites singulares Augusti

Based in Rome, they escorted the Roman emperor whenever he left the city on a campaign or on tours of the provinces.

A second, supplementary, camp was built, also on the Caelian, when the unit was expanded under Septimius Severus; this has been excavated underneath the Basilica of San Giovanni in Laterano, Rome (see Castra Nova equitum singularium).

[5] It has also been claimed that equites singulares were recruited in Italy among natural born Roman citizens.

From the Great Trajanic Frieze incorporated in the Arch of Constantine in Rome, it appears that the emblem of the equites singulares was the scorpion, which was emblazoned on their standards and (fourfold) on their shields.

[7] It appears that after some campaigns, detachments of singulares were left behind in the provinces, to form the core of new regular alae, which retained the prestigious singulares title and crack reputation (e.g., the Ala I Flavia singularium stationed in Raetia in mid-2nd century).