“A lot of it was war, and the refugees they generate.”
Yes, but my problem is this...and I am not arguing with you...I just need to get to an intellectual bottom of this which has fascinated me for long time: About war: Folks were either on foot or the more lucky few were on horseback. Refugees took longer to move about. The plague hit quick and fast at almost at the same time everywhere.
Wikipedia isn't the most authoritative site, but in this case it's probably right: http://en.wikipedia.org/wiki/Black_Death
It took a couple of years to spread, and followed the trade routes. It appeared more than once, but the 1348-50 episode was the worst.
One infected person fleeing from a plague city on horseback can move a pretty good distance quickly, leaving infected fleas every place he stops to sleep. A dozen ships leaving an infected port in Turkey could hit towns from Italy to England to Germany in a few months.
There's not much special in how fast this moved in a time of poor harvests and poor health.
Only if your 'everywhere' is the twenty mile circle around your home.
"Bubonic plague broke out in Central Asia in 1338/39 and reached China and India in 1346.... The epidemic reached the Black Sea port of Caffa by 1347. Fleeing Genoese ships then carried the fleas and their host to Constantinople, Italy, and Marseilles.
"From the prosperous Italian cities, the Black Death spread in waves over western Europe....The plague entered Britain through several ports, among them Bristol, where the plague swept ashore in August 1348. ...By July 1349, the Black Death had reached Scotland,..."
from The Little Ice Age, by Brian Fagan