1. A town close to modern city of Kavala.
2. In this last case, P. Aelius Ballista could belong to that same family, for he originated from the equestrian class and followed a carrier in the military, like Callistus.
3. His presence is reported during the last phase of the campaign (259-260). It is possible that he was in that post since 253/254, when Valerian launches his offensive against the Persians.
4. SHA, Val. 4.4; Zonar. 12.23; Sygg. 716.
5. SHA, Gal. 1.2, Tyr. Trig. 12.1. The view expressed in CAH XII, p. 172 (A. Alfoldi) that he was eliminated from the contention of the throne because he was of low birth is unsupported.
6. SHA, Gal. 3.2-4, Tyr. Trig. 14.1, 15.4, 18.1-3, 18.12; Zonar. 12.24. The reference to his self-proclamation as emperor is considered untrustworthy. Even the coins he is said to have minted are considered spurious, RE II.2 (1896), column 2831, see under entry “Ballista (2)” (W. Henze).
7. Birley, E., "Ballista and ‘Trebellius Pollio’", in Straub, J. (ed.), Bonner Historia-Augusta-Colloquium 1984/1985 (Antiquitas 4.16, Bonn 1987), pp. 56-58; Chastagnol, A., "Végèce et l'Histoire Auguste", in Bonner Historia-Augusta-Colloquium 1971 (Antiquitas 4.11, Bonn 1974), p. 73; Mazzarino, S., "Precetti del buon governo (praecepta gubernandae rei p.) e problemi di economia militare", in Bonner Historia-Augusta-Colloquium 1971 (Antiquitas 4.11, Bonn 1974), pp. 103-112.