We all realize that temperature is not a constant.  It’s hard enough to imagine what life was like in the Middle Ages, without adding in differences in temperature.  As it turns out, many of my books falls directly into the ‘medieval warm period’ of 950 to 1250.

“The Medieval Warm Period (MWP) is generally thought to have occurred from about AD 950–1250, during the European Middle Ages.^[9] In 1965 Hubert Lamb, one of the first paleoclimatologists, published research based on data from botany, historical document research and meteorology combined with records indicating prevailing temperature and rainfall in England around 1200 and around 1600. He proposed that “Evidence has been accumulating in many fields of investigation pointing to a notably warm climate in many parts of the world, that lasted a few centuries around A.D. 1000–1200, and was followed by a decline of temperature levels till between 1500 and 1700 the coldest phase since the last ice age occurred.”^{[14]  http://en.wikipedia.org/wiki/Medieval_Warm_Period}

Not only should this chart put to rest any notion that global warming doesn’t exist, but it calls attention to two different climate periods in Europe:  “The Medieval Warming Period”, which began around 950 AD and ended around 1300 AD, which was followed by a ”Little Ice Age” which lasted until the middle of the 19th century.

On the NOAA web page:  “Norse seafaring and colonization around the North Atlantic at the end of the 9^th century indicated that regional North Atlantic climate was warmer during medieval times than during the cooler “Little Ice Age” of the 15^th – 19^th centuries. As paleoclimatic records have become more numerous, it has become apparent that “Medieval Warm Period” or “Medieval Optimum” temperatures were warmer over the Northern Hemisphere than during the subsequent “Little Ice Age”, and also comparable to temperatures during the early 20^th century” before the temperatures started to rise precipitously.

The warming period, followed by the cooling period affected the climate and population of Europe (and for my purposes, Wales).   Wales is mountainous and rocky, and the warmer air ushered in a period of prosperity in which the population doubled between 950 AD and 1350 AD, when the population was decimated by the Black Plague.   The population of Wales didn’t exceed 1350 levels again until the 16th century. (see my post here)

Glacial Ice began expanding in 1250 AD, but did not seriously impact much of Europe until the mid-1500s. Mann writes:  “In the Chamonix valley near Mont Blanc, France, numerous farms and villages were lost to the advancing front of a nearby mountain glacier. The damage was so threatening that the villagers summoned the Bishop of Geneva to perform an exorcism of the dark forces presumed responsible.”   (Little Ice Age) Unfortunately for the villagers, the attempts were unsuccessful