Hmmm. It was generally known that the Vandals had, like the Visigoths, sacked Rome (410, Visigoths; 455, Vandals). In the 16th and 17th century English sources they are usually part of a list (Huns, Goths and Vandals), like Dryden's
Till Goths, and Vandals, a rude Northern race, Did all the matchless Monuments deface
I don't know how early it turns into *just* Vandals. It might be earlier in French. I'd hesitate to call it propaganda - just exagerration. --MichaelTinkler