Cohors IV Breucorum were first attested garrison unit at Ebchester, identified from the early-third century altar to Minerva the Roman war goddess (RIB 1101; altarstone; AD213-22) and also on an undated but probably contemporary building inscription (RIB 1113). They 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. An inscription from Bowes in Durham attributed to Cohors IIII Frisiavonum may actually belong to this unit.
