The fourteenth century was an age of transition in the recruitment of armies in the Low Countries. In the princely host, the traditional feudal ties remained important, but they underwent a process of multiplication and diversification. In this article, we explore the changing nature of these feudal relations and other bonds, and the consequences for the power relationships between princes and their vassals in the later Middle Ages. It discusses the implications of five types of ties between a prince and the men who fought in his army. These five forms of military recruitment were triggered by the increasingly business-like way in which princes raised their armies, and mark the transition from a feudal host to a contract army. For a long time the feudal host remained the core of the army, but the underlying feudal relations became increasingly monetarised through the granting of fief-rentes and fief-rentes de reprise. In this, the feudal ties and military contracts in the Low Countries show striking similarities to bastard feudalism in England, although there are also important differences.