When and how did the word “vandal” become a curse? What did it mean before?

During the Great Migration, the Baltic tribe of the Wends split in two. The eastern part moved to the future Poland and Russia (Vendichi, they are also Vyatichi). The western part (Vandals) passed through Gaul, Iberia, settled in North Africa, in 455 robbed Rome. For this barbaric devastation of the City, Roman historians called the Vandals “the worst of the barbarians.”