Carolingians founded and enriched monasteries and other Christian holy sites. Large amounts of moveable wealth were placed in the hands of monks: physically the weakest men in society.
The reasons for this explosion in monasticism around the turn of the first millennium have been hotly debated by historians. Many factors played a part. One elemental cause may have been climate change. Between around 950 and 1250 global temperatures in the northern hemisphere rose, and although this rise was by no means evenly felt across the globe, it provided the longest sustained period of benign climate conditions in the west since the Roman Climate Optimum. Although as we shall see, the so-called Medieval Warm Period would not last throughout the Middle Ages, it made conditions in Europe relatively favourable to agriculture. This natural advantage coincided with the development of new horse-harnesses and large iron ploughs (‘heavy’ ploughs) which allowed massively more efficient large-scale agriculture.25 And as this technology combined with the effects of a fluctuating climate, landholding became ever more profitable and landowners had ever more disposable income to spend. But what to spend it on? One very good answer was: salvation.