abbozzerei un
"(qualunque sia il soggetto della frase) was/had been/is(dipende dal tempo della frase che non è riportato) inspired by visionary artists like the formerly unknown Van Gogh and Turner"
ora vado a postare la domanda per cui mi son registrato
When I first read this, I took it to mean not that Van Gogh and Turner were formerly unknown, but that there had been no previous examples of artists with comparable vision. Could that be a valid interpretation?