Borstobass? That's a fucking Crimean Peninsula and Bosporan Kingdom, isn't it. Oh my fucking god.
So, the beastmen are Romans and king is Vespasian. LOL!
Actually scratch that, since "Osmalgo" is right across the sea, that makes them the Ottomans. Even the Ottoman-aligned city-states to the west fit. Oh my.
That would make Saliphie a reference to Hurrem Sultan (which also fits nicely, with her being 'sold' to be a sacrifice) and then the king would be Suleiman the Magnificent.