This dissertation proposes a new model for examining the political strategies of noble families during the central Middle Ages. It uses the German noble house of Andechs as a case study to argue that the analysis of family relationships is critical to understanding how noblemen and noblewomen exercised their lordship and expanded their power. The kinship networks active within the Andechs family are shown to be the principal reason why this noble house became during the twelfth century one of the most influential families in the German empire. Part I's introductory chapters assert that recent scholarly approaches to the medieval nobility in general (Chapter One) and the house of Andechs in particular (Chapter Two) are inadequate for explaining the roles kinship played in medieval politics. The chapters in Part II demonstrate how two of the most popular source bases used by historians of the nobility, property donations (Chapter Three) and memorial records (Chapter Four), are unreliable as evidence for kinship networks because they reveal more about the interests of the religious communities who wrote the texts than they reveal about the families who are named in the documents. Part III proposes a series of new directions in the study of medieval noble houses. First, the family relationships of the secular lords who belonged to the Andechs lineage are analyzed to explain how these interactions affected decisions concerning succession (Chapter Five). The roles Andechs churchmen played inside their family's networks of cooperation and support are then considered (Chapter Six). Lastly, despite a problematic source base, Andechs women's family relationships are explored to determine their potential significance for the noble house's politics (Chapter Seven). This study concludes in Part IV (Chapter Eight) by arguing that the political success of the house of Andechs in the twelfth century can only be appreciated by reconstructing the kin networks on which family members relied as they sought to expand their positions in the empire. Through the examination of a single noble house, this dissertation seeks to demonstrate how the analysis of family relationships can provide new perspectives on medieval politics and noble society.