From The Heretic Knowledge Vault
A sword bearing a Durus Flamma blade, at least in principle. It's unclear whether we have seen a real one, although monk-wannabe Chris uses what appears to be a mock Spatha in his sparring match with Sara (which of course turns out disastrously for him). According to the Poe notes in the Durus Flamma article, this type of sword is fairly common among the Ensigerum.
There was a real-world version of the Spatha, according to Wikipedia. Interestingly, it developed some time after the real-world harpe, just as the Spatha of the Poe-verse did after the Hape. Life imitates art, it seems.