Yersinia pestis

And nobody at the time knows what's causing it.

We know now it was a bacterium called Yersinia pestis, and it rides in the guts of fleas.

Ugh.

Today, a course of antibiotics clears it up.

It is also, unfortunately, wrong.

The mountains proved no more a barrier to Yersinia pestis than the English Channel had been.

And while German record-keeping in this period lagged well behind the meticulous documentation of Italy or England, leaving historians with frustratingly incomplete ledgers of the dead, the surviving evidence points to a death toll by thirteen fifty that stood shoulder to shoulder with its Western neighbors.

The paper trail runs thin, but the human trail does not.

But Alfonso would not break the siege, would not abandon his soldiers to save himself.

Whether one calls it nobility or stubbornness, and perhaps in a man the two are rarely so far apart, it cost him his life.

He remains history's singular reminder that when Yersinia pestis came calling, it observed no protocol of rank and bowed to no throne.

From there, the plague simply kept walking.