Legio II Herculia was a Roman legion

Roman legion

A Roman legion normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but they were typically composed of perhaps 5,000 soldiers, divided into maniples and later into "cohorts"...

, levied by Emperor Diocletian

Diocletian

Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244  – 3 December 311), was a Roman Emperor from 284 to 305....

 (284-305), possibly together with I Iovia

Legio I Iovia

Legio I Iovia was a Roman legion, levied by Emperor Diocletian , possibly together with II Herculia, to guard the newly created province of Scythia Minor...

, to guard the newly created province of Scythia Minor

Scythia Minor

Scythia Minor, "Lesser Scythia" was in ancient times the region surrounded by the Danube at the north and west and the Black Sea at the east, corresponding to today's Dobruja, with a part in Romania and a part in Bulgaria....

. It was stationed at Capidava

Capidava

Capidava is a South American spider genus of the Salticidae family .-Species:* Capidava annulipes Caporiacco, 1947 — Guyana* Capidava auriculata Simon, 1902 — Brazil* Capidava biuncata Simon, 1902 — Brazil...

. The cognomen

Cognomen

The cognomen nōmen "name") was the third name of a citizen of Ancient Rome, under Roman naming conventions. The cognomen started as a nickname, but lost that purpose when it became hereditary. Hereditary cognomina were used to augment the second name in order to identify a particular branch within...

 of this legion came from Herculius, the attribute of Maximian

Maximian

Maximian was Roman Emperor from 286 to 305. He was Caesar from 285 to 286, then Augustus from 286 to 305. He shared the latter title with his co-emperor and superior, Diocletian, whose political brain complemented Maximian's military brawn. Maximian established his residence at Trier but spent...

 (Diocletian's colleague) meaning "similar to Hercules".

According to Notitia Dignitatum

Notitia Dignitatum

The Notitia Dignitatum is a unique document of the Roman imperial chanceries. One of the very few surviving documents of Roman government, it details the administrative organisation of the eastern and western empires, listing several thousand offices from the imperial court down to the provincial...

, at the beginning of the 5th Century II, Herculia was still in its camp on the Danube

Danube

The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

.