sentences:  On 28 October 1412, Queen Margaret I of Denmark died of the Plague aboard a ship in Flensburg Harbour.From time to time plagues such as bubonic plague, caused mainly by rat fleas (Xenopsylla cheopis, a parasite found on brown rats), "red" dysentery and other scourges killed a great deal of Flensburg's population.Lepers were strictly isolated, namely at the St.-Jürgen-Hospital ("Helligåndshospital", built before 1290), which lay far outside the town's gates, where the St. Jürgen Church is nowadays.