During the sixteenth century, cavalry organizations across Europe transformed in different ways. This article examines the development of a new type of cavalry in Sweden during the first decades of the reign of King Gustav Vasa. It focuses on the methods of recruitment and examines to what extent and on what conditions foreign cavalry served in Sweden during this period, how they were organized, and what role they arguably played in the formation of a new domestic cavalryorganization. Building on novel findings the study provides a detailed example of the transformation of the cavalry organization with rare glimpses into the service conditions of the German petty cavalry contractor. In Sweden, there was no uniform type of contract and several categories of foreign horsemen served in parallel, mostly on annual contracts. The king seems to have valued the expertise provided by the foreign professionals. Many were integrated into the Swedish military organization and provided military expertise in the creation of a new domestic Swedish cavalry organization. Unlike Denmark and Poland where a modernized cavalry gradually grew within existing organizations, in Sweden, Gustav Vasa created entirely new units of enlisted domestic cavalry on the model of the German mercenary cavalry.