abstract:Cniva (Kniwa, meaning "knife") (flourished mid-3rd century CE) was the Gothic chieftain who invaded the Roman Empire in the third century CE. He successfully conquered the city of Philippopolis, present-day Bulgarian city Plovdiv, and killed the emperor Decius and his son Herennius Etruscus at the Battle of Abrittus as he was attempting to leave the Roman Empire.