There is no recorded full tria nomina (the traditional Roman three-part name) for the commander Pacidius in ancient historical texts.

Why the Name is Incomplete

In the surviving primary source for this campaign—the anonymous Bellum Africum (The African War)—the officer is referred to strictly by his nomen. The historical text completely omits his individual first name (praenomen) and family branch nickname (cognomen). [1, 2, 3, 4, 5]

Scholars and prosopographical records, such as Broughton's Magistrates of the Roman Republic, only preserve the following details about him:

• Praenomen: Unknown / Unrecorded
• Nomen Gentile (Clan Name): Pacideius (frequently corrupted in standard manuscript traditions to Pacidius or Placidius)
• Cognomen: Unknown / Unrecorded [1, 2, 3]

Historical Context at Ruspina

He was one of two Pacidei brothers who served as Pompeian officers and cavalry commanders under the primary leadership of Titus Labienus during the civil war in Africa (46 BC). He fought against Julius Caesar at the Battle of Ruspina and later at the Battle of Tegea, where he was severely wounded after a heavy javelin (pilum) pierced his helmet. [1, 2, 3, 4, 5]

Because Roman authors often referred to lesser-known military officers and equestrian-rank commanders solely by their clan name (nomen), his full tria nomina was lost to history. [1, 2]

The two brothers fought together only once? Who says they were brothers? lat eng

No, they did not fight together only once, and it is the contemporary ancient source Bellum Africum (The African War) that explicitly mentions them acting as a pair of commanders. [1, 2]

Who says they were brothers? / Chi dice che erano fratelli?

The explicit identification of the two Pacidei as brothers comes from standard historical and grammatical analysis of the text.

• Latin: In chapter 13 of the Bellum Africum, the text records: "Hostes interim, quorum dux erat Labienus et duo Pacidei, aciem derigunt...".
• English: "Meanwhile the enemy, whose leaders were Labienus and the two Pacidei, drew up their line..."
• Italian: "Frattanto i nemici, i cui comandanti erano Labieno e i due Pacidei, schierano la linea..." [1, 2, 3, 4]

In Latin historical writing, pluralizing a family name with a numeral—such as duo Pacidei—specifically implies a pair of brothers (fratres). This is why classical indices and dictionaries (such as the Teubner or Loeb Classical Library glossaries) categorize them directly as "Pacidei duo, fratres, Pompeiani" (The two Pacidei, brothers, Pompeians). [1, 2]