As the dagger doesn’t fit into any category, I suppose it's probably a special order. In that case, I don't think the details matter. That's why I say it could even be from the 20th century — it's irrelevant.
But it would be interesting to know who the cutler is and where he's from.
Is that a common tang? Are there any similar ones? I think that would be a good clue, as well as what appears to be the signature “Jst.”, of course.
"The best-known story of St George concerns the slaying of a fearsome dragon that lived in Silene, in Libya.
To appease the dragon’s fury, the inhabitants offered the monster two sheep a day. At a certain point, the dragon became more demanding and demanded a human sacrifice. The choice fell at random upon the only daughter of the King of Libya.
At that tragic moment, St George appeared, offering to fight the dragon and free the city from that terrible yoke. He mounted his horse and, with a spear, wounded the dragon. Bringing it bound into the city, he killed it before all the inhabitants, after demanding in return their conversion to Christianity."
in
https://www.infopedia.pt/recursos/le...rge-e-o-dragao
https://en.wikipedia.org/wiki/Saint_...and_the_Dragon
So there we have St George with his spear and the daughter of the King of Libya, and they lived happily ever after.