Wikipedia
Ministerialis (plural ministeriales; a post-classical Latin word, used in English, meaning originally "servitor" or "agent", in a broad range of senses) were people raised up from serfdom to be placed in positions of power and responsibility. In the Holy Roman Empire, in the High Middle Ages, the word and its German translations, Ministeriale(n) and Dienstmann, came to describe those unfree nobles who made up a large majority of what could be described as the German knighthood during that time. What began as an irregular arrangement of workers with a wide variety of duties and restrictions rose in status and wealth to become the power brokers of an empire. The ministeriales were not legally free people, but held social rank. Legally, their liege lord determined who they could or could not marry, and they were not able to transfer their lords' properties to heirs or spouses. They were, however, considered members of the nobility since that was a social designation, not a legal one. Ministeriales were trained knights, held military responsibilities and surrounded themselves with the trappings of knighthood, and so were accepted as noblemen. Both women and men held the ministerial status, and the laws on ministeriales made no distinction between the sexes in how they were treated.