Cohors IV Breucorum were a five-hundred strong infantry regiment originally levied from amongst the Breuci tribe of Pannonia Inferior, natives of the Bosna valley in north-eastern Bosnia-Herzegovina. They were the first attested garrison unit at Ebchester, identified from the early-third century altar to Minerva the Roman war goddess (RIB 1101; altarstone; 213-22AD) and also on an undated but probably contemporary building inscription (RIB 1113). An inscription from Bowes in Durham attributed to Cohors IIII Frisiavonum may actually belong to this unit.
- Burn 100; CIL XVI.65 military diploma dated: July 17th 122AD.
- L’Année Épigraphique 1997.1779b diploma dated c.126AD.
- Bowes? (RIB 739 130-133AD).
- Ebchester (RIB 1101 altar, dated: 213-222AD; 1113).