Servius made the Comitia Centuriata the sovereign assembly of the nation; and he accordingly transferred to it from the Comitia Curiata the right of electing kings and the higher magistrates, of enacting and repealing laws, and of deciding in cases of appeal from the sentence of a judge. But he did not dare to abolish the old Patrician assembly, and was even obliged to enact that no vote of the Comitia Centuriata should be valid till it had received the sanction of the Comitia Curiata. Thus, in consequence of the legislation, we shall find that Rome subsequently possessed three sovereign assemblies: 1. The _Comitia Centuriata_, consisting of both Patricians and Plebeians, and voting according to Centuries; 2. The _Comitia Curiata_, consisting exclusively of Patricians, and voting according to Curiae; 3. The _Comitia Tributa_, exclusively of Plebeians, and voting according to Tribes. II. The second great work of Servius was the extension of the Pomoerium, or hallowed boundary of the city, and the completion of the city by incorporating with it the Quirinal, Viminal, and Esquiline Hills.[9] He surrounded the whole with a stone wall, called after him the wall of Servius Tullius; and from the Porta Collina to the Esquiline Gate, where the hills sloped gently to the plain, he constructed a gigantic mound nearly a mile in length, and a moat 100 feet in breadth and 30 in depth, from which the earth of the mound was dug. Rome thus acquired a circumference of five miles, and this continued to be the legal extent of the city till the time of the emperors, although suburbs were added to it. III. An important alliance with the Latins, by which Rome and the cities of Latium became the members of one great league, was one of the great events which distinguished the reign of Servius. [Illustration: Map of Rome, showing the Servian Wall and the Seven Hills.]