The present paper aims at investigating the role of court officials in the judicial system of Umma during the Ur III period. For this purpose, a prosopographical study of judges, commissioners, military men, merchants, and other members of the royal, provincial and local administrations has been made. In conclusion, a judicial system with the governor as the highest authority, but with a strong presence of the royal administration, and particularly of the military, is sketched. This article is a much revised and expanded version of a paper presented at the 53e Rencontre Assyriologique Internationale at St. Petersburg, in July 2007. This research has been made possible thanks to the financial support granted by the Spanish Ministerio de Economía y Competividad through the project FFI2011–23981. I wish to express my warm thanks to Piotr Steinkeller and Walther Sallaberger, who read the manuscript of this work and made helpful and valuable suggestions; Piotr Steinkeller generously shared with me some of his yet unpublished and impressive manuscripts. I would also like to thank Steven Garfinkle, who kindly revised my English and offered very helpful comments. Abbreviations follow those of BDTNS (http://bdtns.filol.csic.es)