After the collapse of the Roman Empire, life in Western Europe was nothing more than a series of wars, food shortages, and disease epidemics. Then, around 1000, things started to get better. Suddenly, there were fewer conflicts and invasions. The result was that there was greater stability. Then, more luck occurred when between 1000 and 1400 there were no serious disease outbreaks. Then, weather patterns changed. Milder winters and warmer summers brought about an increase in agriculture production. Old towns were now being invigorated, and new major centers of commerce were emerging.
Now, Jewish merchants linked Western Christendom with the wealthy civilizations of Islam and Byzantium. They traded in slaves, salt, grain, and wine. Commerce exploded as cities were back. Great trading cities emerged like Venice, Genoa, and Pisa. These cities were filled with merchants, and they helped connect the east with the west. International trade flourished, Paris exported grain, Scandinavia exported lumber, Germany exported fish and salt, and Burgundy exported wine. Aristocrats could now spoil themselves with imported luxury goods, and money was now flowing in silver coins instead of commodities. It was this money that built the amazing cathedrals, and supported the crusades, as well as supported the Catholic charities.
As the population increased so did the problems that were associated with it. Farming was now expanding in all directions. As a result swamps were drained and forests were cleared. Farmers now used a heavy-wheeled plow that eliminated the need for cross plowing. Also, they adopted a three field agricultural system that increased production dramatically. Under this new system, 1/3rd of the field was planted in winter barley, wheat, or rye, while another third was planted in the spring with corn, beans, or peas. The remaining 1/3rd was left to fallow. Also, the work capacity of horses was increased by 4 times, making them a better bargain than slaves. Tandem horses with padded collars, and nailed horseshoes were all introduced. As a result there was less need for human labor. Two more major inventions decreased the need for slaves. Wind and water mills now grounded grain, sawed lumber, and crushed ore. These mills provided services for as many as fifty families. Another great invention of the High Middle Ages was the spinning wheel. The spinning wheel changed the way everyone lived. It made cloth and thread inexpensively. Now everyone had underwear, bed sheets, towels, and a large variety of clothing to chose from. When the clothing wore out people in the Middle Ages used the rags to make cheap paper. By 1300, the mechanical clock was in regular use.
During this time period, London was the largest city in Europe with 30,000 people. Its mud streets were lined with houses and shops that were built of wood. During the day the streets were packed with horses, dogs, vendors, and people. They had sanitation workers who picked up the garbage and even had a sewer system. The merchants traded with every known nation in the world.