 Like medieval Jewish groups, the Dwarves use their own language only amongst themselves, and adopted the languages of those they live amongst for the most part, for example taking public names from the cultures they lived within, whilst keeping their "true-names" and true language a secret.Along with a few words in Khuzdul, Tolkien also developed runes of his own invention (the Cirth), said to have been invented by Elves and later adopted by the Dwarves.Tolkien further underlines the diaspora of the Dwarves with the lost stronghold of the Mines of Moria.