While Europe may not have been the first continent to brew beer, it certainly has one of the most influential histories, with the Medieval period perhaps showing the biggest beer boom as it was one of the most common beverages in Europe during the middle ages. During this period, brewing began shifting from individual families to Monasteries and convents. Hops began to be introduced into the beer making process rather than herbs for the bitterness. Toward the end of the middle ages, commercial brewing was popular in Germany, Austria and England. During the Renaissance period (1516), Reinheitsgebot, the German Purity Law, was introduced. It stated the only ingredients allowed in the beer-making process were water, barley and hops. Yeast was still thought to be a byproduct of fermentation rather than a necessity. In 1810, Munich established Oktoberfest and lagers started to become popular. Prior to that, most beer was basically Ales. Recently, the craft beer enthusiasm in the United States has found it way to Europe, with recent phenomenal growth in many parts of Europe. The rich brewing history in Belgium has produced the best beer in Europe and perhaps the best beer in the world.