Postumus, commander of the Roman Rhine armies defeated the Franks south of the Rhine in 260. Emperor Gallienus could not do the job because he was fighting other invaders in Italy and Pannonia. The father of Gallienus, Valerian was captured by king Shapur I of Persia when the Romans lost the Battle of Edessa in 259 or 260, leaving Gallienus as main ruler of the Roman Empire.
While the Franks reached Tarraco in Spain, the Alamanni reached the outskirts of Rome in 259. On the way back, Gallienus defeated them at the Battle of Mediolanum in 259. The Agri Decumates was never recovered from the Alamanni.
While Postumus was busy defeating the Franks in 260, the Sarmatians invaded Pannonia and Illyricum. Governor Regalianus of Illyricum declared himself emperor, because there was no Roman army to fight the invaders. His quickly gathered force was defeated in Pannonia where he was killed. Gallienus defeated the Sarmatians in Panonia, but had to deal with an invasion of the Roxolani. The Scythians caused havoc south of the Danube further downstream, sacking Athens. King Shapur of Persia sacked Antioch again and devastated Cilicia and Cappadocia. A remnant of the Roman army under Balista chased him away. The governor of Syria, prince Odaenathus of Palmyra, defeated the retreating Persian army.