Cniva

He successfully captured the city of Philippopolis (Plovdiv in Bulgaria) in 250 and killed Emperor Decius and his son Herennius Etruscus at the Battle of Abritus as he was attempting to leave the Empire in 251.

Cniva's main column under the King himself crossed the Danube at Oescus then headed eastwards to Novae, where he was repelled by the provincial governor (and future emperor) Trebonianus Gallus.

[3] After these initial setbacks, the Goths moved southwards through the Haemus mountain and Decius pursued them (likely through the Shipka Pass) to save Philippopolis.

Decius was forced to withdraw his army to the north at Oescus, leaving Cniva ample time to ravage Moesia and finally capture Philippopolis in the summer of 251, in part with the help of its commander, a certain Titus Julius Priscus who had proclaimed himself Emperor.

[4] The sack of Philippopolis invigorated Decius, who intercepted several parties of Germans, and repaired and strengthened his fortifications along the Danube, intending to oppose Cniva’s forces.

[10] Jordanes and Aurelius Victor claim that[11] Herennius Etruscus was killed by an arrow during a skirmish before the outset of the battle and that his father addressed his soldiers as if the loss of his son did not matter.