Crusades and the weather...

de bene esse: literally, of well-being, morally acceptable but subject to future validation or exception

http://www.medievalists.net/2013/12/16/a-climate-for-crusades-weather-climate-and-armed-pilgrimage-to-the-holy-land-11th-14th-century/

A Climate for Crusades? Weather, climate and armed pilgrimage to the Holy Land (11th–14th...

medievalists.net

The crusaders found themselves confronted not only with foreign cultures and violent armed resistance, but also with an alien natural environment and climatic conditions that could prove to be sometimes just as fatal as the arrows of the enemy.