During the early Middle Ages, hundreds of feudal nobles ruled over territories of varying size. Feudal nobles had their own courts and armies and collected their own taxes. Most feudal lords acknowledged a king or other overlord, but royal rulers had little power. The Church, too, was a center of power with its own laws, system of justice, and methods of raising money. Both nobles and the Church could at times have as much power as a monarch.
This image from an 11th-century Bible shows a king receiving fealty from his nobles.
From about 1000 to 1300, sometimes called the High Middle Ages, the balance of power slowly shifted. Feudal monarchs began to exert royal authority over their nobles and the Church. Some feudal monarchs succeeded in centralizing power and built the framework for nation-states such as Britain and France. (A nation-state refers to an independent political unit that has a single government and usually shares a common culture and history.)
Monarchs used various means to centralize power. First, they sought to extend royal law and justice over their kingdoms. To do so, they had to crush the power of rival courts of justice run by feudal nobles and the Church. To provide efficient government and a steady source of income, feudal monarchs set up government bureaucracies that administered justice and taxation. With a larger income, monarchs could afford to support a standing army, rather than rely on the military service of their nobles.