the plural (often dual) and some legions are known to have had multiple praefecti castrorum.Keppie (1998), p. 177. The title is given in the singular on the memorial plaque, though, so we might have a scribal error on the sarcophagus. If not, then Castus was probably one of two prefects of this legion. Dux Legionum Trium "Britanicimiarum" Before finishing his military career, Castus led an expedition of some note as a Dux Legionum, a temporary title accorded to officers who were acting in a capacity above their rank, either in command of a collection of troops (generally combined vexillations drawn from legions) in transit from one station to another or in command of a complete unit (the former seems to be the case with Castus, since the units are spoken of in the genitive plural). Adversus *Arm[oric(an)o]s or Adversus *Arme[nio]s? For many years it has been believed that Castus's expedition was against the Armoricans (based on the reading ADVERSUS ARM[....]S, reconstructed as "adversus *Armoricanos" – "against the Armoricans" – by Theodor Mommsen in the CIL and followed by most subsequent editors of the inscription), but the earliest published reading of the inscription, made by the Croatian archaeologist Francesco Carrara in 1850, was ADVERSUS ARME[....], with a ligatured ME (no longer visible on the stone, possibly due to weathering, since the stone has been exposed to the elements for centuries and was reused as part of a roadside wall next to the church of St. Martin in Podstrana; the mutilated word falls along the broken right-hand edge of the first fragment of the inscription). If Carrara's reading is correct, the phrase is most likely to be reconstructed as "adversus *Armenios", i.e. "against the Armenians", since no other national or tribal name beginning with the letters *Arme- is known from this time period. The regional names Armoricani or Armorici are not attested in any other Latin inscriptions, whereas the country Armenia and derivatives such as the ethnic name Armenii and personal name Armeniacus are attested in numerous Latin inscriptions. Furthermore, no classical sources mention any military action taken against the Armorici/Armoricani (which was in origin a regional name that encompassed a number of different tribes) in the 2nd or 3rd centuries. While there are literary references to (and a small amount of archaeological evidence for) minor unrest in northwestern Gaul during this time period – often referred to as, or associated with,