The Herules (or Heruli) were an East Germanic tribe who lived north of the Black Sea apparently near the Sea of Azov, in the third century AD, and later moved (either wholly or partly) to the Roman frontier on the central European Danube, at the same time as many eastern barbarians during late antiquity, such as the Goths, Huns, Scirii, Rugii and Alans.
In the third century, they were named along with Goths as one of the most important "Scythian" groups who attacked Greece from the Black Sea by sea, and marauded around the Balkans for several years. In the fourth century, they were subjugated by the empires of Ermanaric the Ostrogoth, and later Attila the Hun, and they are not mentioned in the written record until after the death of Attila.
Along with many other people they reappear in the written records as one of many groups from the east who were struggled for supremacy on the left bank of the middle Danube after the death of Attila, in the area stretching from modern Bavaria to modern Hungary. They established their own kingdom and many joined Odoacer, who deposed the last Western Roman Emperor Romulus Augustus in 476 AD. They became well known both as soldiers in various Roman armies, in the Italian kingdom of Odoacer, and as sea raiders on the Atlantic coast, before fading out of history. The Danubian kingdom broke up and remnants settled in the Balkans and other places. The last known political entity which was described as Herulian seem to have been in the area of modern Belgrade in the 550s, as a settlement within the Roman empire and under Roman control.