During the Middle ages, from about 800 to 1300, the world went through five centuries of higher temperatures than average…yes, even higher than today.

During this era, the Vikings traveled around the known world–over land to the East, and by sea to the West. Warmer weather in the North meant less difference in temperature between the North and the Equator, hence fewer and less severe storms on the oceans. The higher temperatures also made it possible to grow grain and other food products in more Northern regions, including Greenland. There was a reason why they called it ‘green’ land: it actually was very green during that period. Since Vikings were ale drinkers, they had ale on their ships, rather high alcohol ale. Because of the warmer global climate, they were able to brew it with local grains from many of the territories to which they traveled. They spread their brewing techniques far and wide, even to Newfoundland (Canada), which the Vikings called Vin-land, since they found grapes over there.

Speaking of grapes, the warmer weather permitted grapes to grow in vineyards as far North as Northern England, the Low-Lands (today’s Belgium and the Netherlands) and vast territories in the East. The consumption of wine and beer mingled amongst the classes. Wine had always been reserved for the wealthy, but its new found abundance allowed it to spread down the hierarchical ladder of society. The line between wine and beer drinkers had also been geographically defined, since locals drank alcoholic beverages made from what was locally available, grapes or grains. That changed: brewers and vintners lived on the same lands now.

Thanks to the abundance of food produced during the constant good weather in that era, the population doubled or even tripled in some places, where it had been constant during the colder era (300-800 a.d.). The abbeys, who were so important in spreading the brewing technique and the cultivation of yeast-strings, became very rich and powerful. Less flooding (less strong storms) allowed them, for example, to create “new land” in vast quantities on the sea in today’s Flanders (Belgium) by building dikes. The cities emerged because each harvest produced more food, and more children stayed alive to become adults thanks to better weather and better food. International trade flourished over land (roads were not washed away as often as in the past) and over sea (less intense storms, more predictable weather). Thanks to the global warming in that era the brewing and consumption of good beer multiplied. More people, more successful people (cities, abbeys), more thirsty people, better grains cultivated in more territories were all factors that contributed in the creation of many new and diverse styles of beer. Wine making and beer brewing techniques influenced each other, especially in today’s Belgium, where rich cities, free from Royal rule, took advantage of the abundance and the freedom to trade.

The overall wealth was so great, optimism so high, food growing so easily, that nobility of the era in Western Europe could look beyond their borders. They were able to take a large number of their men, much of their treasure, and travel to the Middle East in an attempt to liberate the region from the Muslims, who had invaded and enslaved all the Christian lands. Indeed, this was the beginning of the Crusades, and there were many of these organized mass summer trips.