Carpi (people) in the context of "Galerius"

Diocletian (/ˌdaɪ.əˈkliːʃən/ DY-ə-KLEE-shən; Latin: Gaius Aurelius Valerius Diocletianus; Ancient Greek: Διοκλητιανός, romanized: Diokletianós; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia. As with other Illyrian soldiers of the period, Diocles rose through the ranks of the military early in his career, serving under Aurelian and Probus, and eventually becoming a cavalry commander for the army of Emperor Carus. After the deaths of Carus and his son Numerian on a campaign in Persia, Diocles was proclaimed emperor by the troops, taking the name "Diocletianus". The title was also claimed by Carus's surviving son, Carinus, but Diocletian defeated him in the Battle of the Margus.

Diocletian's reign stabilized the empire and ended the Crisis of the Third Century. He initiated the process of the Roman Empire split and appointed fellow officer Maximian as Augustus, co-emperor, in 286. Diocletian reigned in the Eastern Empire, and Maximian reigned in the Western Empire. Diocletian delegated further on 1 March 293, appointing Galerius and Constantius as junior colleagues (each with the title Caesar), under himself and Maximian respectively. Under the Tetrarchy, or "rule of four", each tetrarch would rule over a quarter-division of the empire. Diocletian secured the empire's borders and purged it of all threats to his power. He defeated the Sarmatians and Carpi during several campaigns between 285 and 299, the Alamanni in 288, and usurpers in Egypt between 297 and 298. Galerius, aided by Diocletian, campaigned successfully against Persia, the empire's traditional enemy, and in 299, he sacked their capital, Ctesiphon. Diocletian led the subsequent negotiations and achieved a lasting and favorable peace.

Aurelian (/ɔːˈriːliən/; Latin: Lucius Domitius Aurelianus; 9 September c. 214 – c. November 275) was a Roman emperor who reigned from 270 to 275 during the Crisis of the Third Century. As emperor, he won an unprecedented series of military victories which reunited the Roman Empire after it had nearly disintegrated under the pressure of barbarian invasions and internal revolts. For his success in restoring the Empire's territorial integrity, Aurelian was honored with the title Restitutor Orbis ("Restorer of the World"). Born in modest circumstances, most likely in Moesia Superior, he entered the Roman army in 235 and climbed up the ranks. He went on to lead the cavalry of the emperor Gallienus, until Gallienus' assassination in 268. Following that, Claudius Gothicus became emperor until his own death in 270. Claudius' brother Quintillus then ruled for three months, before Aurelian took the empire for himself. Aurelian was chosen Roman emperor by the Illyriciani as one of themselves.During his reign, he defeated the Alamanni after a devastating war. He also defeated the Goths, Vandals, Juthungi, Sarmatians, and Carpi. Aurelian restored the Empire's eastern provinces after his conquest of the Palmyrene Empire in 273. The following year he conquered the Gallic Empire in the west, reuniting the Empire in its entirety. He was also responsible for the construction of the Aurelian Walls in Rome, the abandonment of the province of Dacia, and monetary reforms attempting to curb the devaluation of the Roman currency.Although Domitian, two centuries earlier, was the first emperor who had demanded to be officially hailed as dominus et deus ('master and god'), these titles never occurred in written form on official documents until the reign of Aurelian. His successes were instrumental in ending the crisis.

The Free Dacians (Romanian: Dacii liberi) is the name given by some modern historians to those Dacians who remained outside, or emigrated from, the Roman Empire after the emperor Trajan's Dacian Wars (AD 101-6). Dio Cassius named them Dakoi prosoroi (Latin: Daci limitanei) meaning "neighbouring Dacians".

A population of Dacians existed on the fringes of the Balkan Roman provinces, especially in the eastern Carpathian Mountains, at least until about AD 340. They were responsible for a series of incursions into Roman Dacia in the period AD 120-272, and into the Roman Empire south of the Danube after the province of Dacia was abandoned by the Romans around AD 275.