This volume publishes the results from a conference held in 2015 on “the lord bishop”, Dominus Episcopus, discussing various functions and roles of bishops during the Middle Ages, covering the early to the late medieval period in mainly Northern Europe (England, Sweden, Denmark and Germany) and also Spain. For the early medieval period, the bishops’ role in relation to and upholding canon law in pre-Viking Anglo-Saxon England is considered, moreover their role in everyday pastoral activities, as well as their relation to monasteries. For the middle medieval period, the role of bishops in warfare, especially in relation to the crusades, is discussed, but also their behaviour in relation to (and violations of) ecclesiastical norms and regulations. Lastly, Scandinavian bishops and their political and military involvement during the late medieval period, the Castilian episcopacy and their relation to the royal court, and finally three archbishops competing over the archbishop’s see in Uppsala in the late medieval period are discussed.