A missus dominicus (plural missi dominici), Latin for "envoy[s] of the lord [ruler]" or palace inspector, also known in Dutch as Zendgraaf (German: Sendgraf), meaning "sent Graf", was an official commissioned by the Frankish king or Holy Roman Emperor to supervise the administration, mainly of justice, in parts of his dominions too remote for frequent personal visits. As such, the missus performed important intermediary functions between royal and local administrations. There are superficial points of comparison with the original Roman corrector, except that the missus was sent out on a regular basis. Four points made the missi effective as instruments of the centralized monarchy: the personal character of the missus, yearly change, isolation from local interests and the free choice of the king.
Based on Merovingian ad hoc arrangements, using the form missus regis (the "king's envoy") and sending a layman and an ecclesiastic in pairs, the use of missi dominici was fully exploited by Charlemagne (ruling 768—814), who made them a regular part of his administration, "a highly intelligent and plausible innovation in Carolingian government", Norman F. Cantor observes, "and a tribute to the administrative skill of the ecclesiastics, such as Alcuin and Einhard". The missi were at first chosen from Charlemagne's personal, most trusted entourage, of whatever social degree. Soon they were selected only from the secular and eccesiastical nobility: the entry for 802 in the so-called Lorsch Annals (794–803) states that instead of relying on "poorer vassals", Charlemagne "chose from the kingdom archbishops and bishops and abbots, with dukes and counts, who now had no need to receive gifts from the innocent, and sent them throughout his kingdom, so that they might administer justice to the churches, to widows, orphans and the poor, and to all the people." Presumably the same year the capitulary usually known as the Capitulare missorum generale was issued, which gives a detailed account of their duties and responsibilities. They were to execute justice, to ensure respect for the king, to control the government of the military dukes and administrative counts (then still royal officials), to receive their oath of allegiance, to let the king's will be known, at times by distributing capitularies around the empire, and to supervise the clergy of their assigned region. In short, they were the direct representatives of the king or Holy Roman Emperor. The inhabitants of the district they administered had to provide for their subsistence, and at times they led the host to battle. The missi were protected by a triple wergeld and resistance to them was punishable by death. In addition special instructions were given to various missi, and many of these have been preserved.