Demographic Crises
Progress in Europe
The disease followed trade routes, so it was Constantinople that was first struck, in 1347. It reached Cyprus, the Holy Land, and Egypt in the same year. In October 1347, a Genoese fleet landed at Messina, Sicily and the plague spread across the island that winter. It also entered Barcelona and other Spanish ports.
The plague spread all across Europe during the next two years. It struck Marseilles in January 1348. It reached Paris in the spring 1348 and England in September 1348. Moving along the Rhine trade routes, the plague also reached Germany the Low Countries the same year.
It took longer to reach the periphery of Europe. Norway was hit in May 1349. The eastern European countries were not reached until 1350, and Russia not until 1351. In general it also took a bit longer to reach inland regions, and towns that were away from trade routes.
There were areas never hit by the plague, or at least this first outbreak. Once such was part of Bohemia. No major town was spared, but isolation wasn't a guarantee either, and in some cases we know of one village that was spared while all around it were struck. Even Iceland and Greenland suffered. The plain fact is that we lack the detailed records we'd need to be able to explain the variations in mortality. Certainly to the people at the time it seemed as if the whole world were dying.