Taking advantage of Roman military disarray, a vast number of barbarian peoples overran much of the empire. The Sarmato-Gothic alliance of the lower Danube carried out major invasions of the Balkans region in 252, and in the periods 253–258 and 260–268. The Peucini Bastarnae are specifically mentioned in the 267/268 invasion, when the coalition built a fleet in the estuary of the river "Tyras" (Dniester). The Peucini Bastarnae would have been critical to this venture since, as coastal and delta dwellers, they would have had seafaring experience that the nomadic Sarmatians and Goths lacked. The barbarians sailed along the Black Sea coast to Tomis in Moesia Inferior, which they tried to take by assault without success. They then attacked the provincial capital Marcianopolis (Devnya, Bulgaria), also in vain. Sailing on through the Bosporus, the expedition laid siege to Thessalonica in Macedonia. Driven off by Roman forces, the coalition host moved overland into Thracia, where finally it was crushed by Emperor Claudius II (r. 268–270) at Naissus (269).