The Aletian Pox was a manufactured disease that caused the weakening and eventual collapse of Hieranispol, one of the earliest Duchies of the Saint Montaigne Delta.
Originally derived from a harmless but unsightly ailment common to the indigenous riverfolk (the Balboth people), accounts differ as to the intended result of the creation of the Aletian Pox. While the chief alchemist involved, Rochard Aletious, went to his grave insisting it was meant to act as a pesticide in the muggy Hieranispolian climate, documents uncovered after the Thermoplastene Accord show that the Hieranispolian military was in fact funding the research.
Regardless, the Aletian Pox's inexorable spread through the Hieranispol buried the truth with the Duchy's inhabitants. Fortunately, there have been no reported cases since, and experts agree that the Pox died out with its last victims.