Army, Israel

• Medieval Europe
In the earliest Middle Ages it was the obligation of every noble to respond to the call to battle with his own equipment, archers, and infantry. This decentralized system was necessary due to the social order of the time, but could lead to motley forces with variable training, equipment and abilities. The more resources the noble had access to the better his troops would be.
The knights were drawn to battle by feudal and social obligation, and also by the prospect of profit and advancement. Those who performed well were likely to increase their landholdings and advance in the social hierarchy. The prospect of significant income from pillage, and ransoming prisoners was also important. For the mounted knight war could be a relatively low risk affair.
As central governments grew in power, a return to the citizen armies of the classical period also began, as central levies of the peasantry began to be the central recruiting tool. England was one of the most centralized states in the Middle Ages, and the armies that fought in the Hundred Years' War were, predominantly, composed of paid professionals.