Events By place Roman Empire Valerian, captured by King Shapur I of Persia, and is later killed in captivity. Postumus revolts against Gallienus in Gaul. The western provinces of Britain and Spain join his independent realm—which is called in modern times the Gallic Empire. The Roman fort of Wiesbaden (Germany) is captured by the Alamanni (possibly 260). The Franks, who invaded the Roman Empire near Cologne in 257, reach Tarraco in Hispania. Asia Mesopotania: Odaenathus, the ruler of the… (More on 259)