Erasmus at home (artist's conception)
Undoubtedly based on some historical events, the story of Erasmus Lüger (a.k.a. Erazem Predjamski, seen here in a highly imaginative modern portrait) has been passed along through centuries of oral tradition until virtually every part of it has several mutually incompatible variants. With severe pruning, an editor can reduce the tale to coherence, but accuracy is perhaps beyond anyone’s reach. Without detailed historical knowledge of local events for which documentation may no longer exist (if it ever did), there’s no good way to decide which elements or versions to keep and which to throw out.

The knight Erasmus Lüger may (or may not) have been the son of an Imperial governor of Trieste. Sources agree that he lived and died in the second half of the 15th century, at a time when the Habsburg Emperor Frederick III was at war with the Hungarian King Matthias Corvinus. Erasmus, though a vassal of the Empire, chose to ally himself with Matthias. (Perhaps before, perhaps after — and maybe because of — the events described in the next two paragraphs.)

A friend of Erasmus (who may have been named Andreas Baumkirchner of Vipava) was beheaded (perhaps by Imperial authorities, perhaps not). Later, a favorite of the Emperor, or maybe a kinsman — identified in one account as a military commander named Marshal Pappencheim — spoke insultingly of the dead man in Erasmus’s presence. This happened at the Emperor’s court in Vienna, or else it didn’t.

In any event, Erasmus took offense and slew the besmircher of his late friend’s honor. The Emperor, taking offense in turn, condemned Erasmus to death, and sent a band of mercenaries to pursue him. Escaping (if this was necessary, depending on how and where the previous scene took place), Erasmus holed up with his followers in the cliffside castle, which the Emperor is said to have bestowed on him in 1478, before the aforesaid events occurred.

When the Emperor condemned Erasmus, he became an ally of the King of Hungary, if he wasn’t one already. Ally or not, however, he seems to have operated mostly on his own, following the standard robber-knight protocol of pillage and plunder. No merchant caravan passing through the district was safe, nor was any estate that happened to belong to the Habsburgs. There’s no evidence that he ever shared his takings with the poor, but he apparently became a hero to them anyway; perhaps they were content just to see their oppressors being oppressed for a change.

The robber knight’s wild career provoked Emperor Frederick to further fits of rage, and he ordered the Governor of Trieste, Kaspar Rauber (Ravbar to the Slovenes) — who was obviously not Erasmus’s father — to kill or capture the outlaw. The governor and his troops besieged Predjama Castle for a year and a day. During most of this time the besiegers were much less comfortable than the besieged: they were camped outdoors in all sorts of weather, and their food supply, dependent on wagon transport, was meager and unreliable.

Erasmus, however, had a secret passage from the cave to the surface up above. Another version says that it connected with the cave of Postojna, which sounds unlikely since the rivers in these two cave systems don’t connect, and flow in radically different directions. But perhaps this wasn’t the case in the distant geological era when the upper caves were formed. (Is that possible? Don’t ask me; I’m no speleologist.) At any rate, the robber knight was able to keep his merry men warm and well fed, and they are said to have enjoyed tossing their garbage down the cliff so the besiegers could see how well they were eating. A more kindly version of this tradition has Erasmus sending the Governor, with his compliments, a roast ox at one point and some fresh cherries at another.

Eventually, however, it seems to have occurred to the Governor that covert action offered a better chance of success than orthodox siege tactics. He managed to get to a servant in the castle and bribe him to give a signal when his master was in the privy. So, one day as Erasmus was dealing with this daily necessity, the signal was given, a cannon was aimed, and the privy and its occupant were blown to kingdom come.

Either that, or a catapult was aimed and a load of heavy rocks — either discharged from the catapult or knocked down from above by the shot, did the job. Accounts vary.