What is a loosely organized system of rule in which a powerful lord divides land holding among lesser lords?

The system you are referring to is known as feudalism. In this structure, a powerful lord grants land, called fiefs, to lesser lords or vassals in exchange for loyalty, military service, and various obligations. This hierarchical system creates a network of mutual obligations and protections, with the king at the top, followed by powerful lords, and then lesser nobles, knights, and peasants at the bottom. Feudalism was prominent in medieval Europe and shaped social, economic, and political relationships during that time.