Sulla here began with the partition of functions. At the beginning of this period the arrangement in that respect stood as follows. As formerly there had devolved on the two consuls the collective functions of the supreme magistracy, so there still devolved on them all those official duties for which distinct functionaries had not been by law established. This latter course had been adopted with the administration of justice in the capital, in which the consuls, according to a rule inviolably adhered to, might not interfere, and with the transmarine provinces then existing - Sicily, Sardinia, and the two Spains - in which, while the consul might no doubt exercise his imperium, he did so only exceptionally. In the ordinary course of things, accordingly, the six fields of special jurisdiction - the two judicial appointments in the capital and the four transmarine provinces - were apportioned among the six praetors, while there devolved on the two consuls, by virtue of their general powers, the management of the non-judicial business of the capital and the military command in the continental possessions. Now as this field of general powers was thus doubly occupied, the one consul in reality remained at the disposal of the government; and in ordinary times accordingly those eight supreme annual magistrates fully, and in fact amply, sufficed.

For extraordinary cases moreover power was reserved on the one hand to conjoin the non-military functions, and on the other hand to prolong the military powers beyond the term of their expiry (prorogare). It was not unusual to commit the two judicial offices to the same praetor, and to have the business of the capital, which in ordinary circumstances had to be transacted by the consuls, managed by the praetor urbanus; whereas, as far as possible, the combination of several commands in the same hand was judiciously avoided. For this case in reality a remedy was provided by the rule that there was no interregnum in the military imperium, so that, although it had its legal term, it yet continued after the arrival of that term de jure, until the successor appeared and relieved his predecessor of the command; or - which is the same thing - the commanding consul or praetor after the expiry of his term of office, if a successor did not appear, might continue to act, and was bound to do so, in the consul's or praetor's stead. The influence of the senate on this apportionment of functions consisted in its having by use and wont the power of either giving effect to the ordinary rule - so that the six praetors allotted among themselves the six special departments and the consuls managed the continental non-judicial business - or prescribing some deviation from it; it might assign to the consul a transmarine command of especial importance at the moment, or include an extraordinary military or judicial commission - such as the command of the fleet or an important criminal inquiry - among the departments to be distributed, and might arrange the further cumulations and extensions of term thereby rendered necessary. In this case, however, it was simply the demarcation of the respective consular and praetorian functions on each occasion which belonged to the senate, not the designation of the persons to assume the particular office; the latter uniformly took place by agreement among the magistrates concerned or by lot. The burgesses in the earlier period were doubtless resorted to for the purpose of legitimising by special decree of the community the practical prolongation of command that was involved in the non-arrival of relief[25]; but this was required rather by the spirit than by the letter of the constitution, and soon the burgesses ceased from intervention in the matter. In the course of the seventh century there were gradually added to the six special departments already existing six others, viz. the five new governorships of Macedonia, Africa, Asia, Narbo, and Cilicia, and the presidency of the standing commission respecting exactions[26]. With the daily extending sphere of action of the Roman government, moreover, it was a case of more and more frequent occurrence, that the supreme magistrates were called to undertake extraordinary military or judicial commissions.

Nevertheless the number of the ordinary supreme annual magistrates was not enlarged; and there thus devolved on eight magistrates to be annually nominated - apart from all else - at least twelve special departments to be annually occupied. Of course it was no mere accident, that this deficiency was not covered once for all by the creation of new praetorships. According to the letter of the constitution all the supreme magistrates were to be nominated annually by the burgesses; according to the new order or rather disorder - under which the vacancies that arose were filled up mainly by prolonging the term of office, and a second year was as a rule added by the senate to the magistrates legally serving for one year, but might also at discretion be refused - the most important and most lucrative places in the state were filled up no longer by the burgesses, but by the senate out of a list of competitors formed by the burgess-elections. Since among these positions the transmarine commands were especially sought after as being the most lucrative, it was usual to entrust a transmarine command on the expiry of their official year to those magistrates whom their office confined either in law or at any rate in fact to the capital, that is, to the two praetors administering justice in the city and frequently also to the consuls; a course which was compatible with the nature of prorogation, since the official authority of supreme magistrates acting in Rome and in the provinces respectively, although differently entered on, was not in strict state-law different in kind.

Such was the state of things which Sulla found existing, and which formed the basis of his new arrangement. Its main principles were, a complete separation between the political authority which governed in the burgess-districts and the military authority which governed in the non-burgess-districts, and an uniform extension of the duration of the supreme magistracy from one year to two, the first of which was devoted to civil, and the second to military affairs. Locally the civil and the military authority had certainly been long separated by the constitution, and the former ended at the pomerium, where the latter began; but still the same man held the supreme political and the supreme military power united in his hand. In future the consul and praetor were to deal with the senate and burgesses, the proconsul and propraetor were to command the army; but all military power was cut off by law from the former, and all political action from the latter. This primarily led to the political separation of the region of Northern Italy from Italy proper. Hitherto they had stood doubtless in a national antagonism, inasmuch as Northern Italy was inhabited chiefly by Ligurians and Celts, Central and Southern Italy by Italians; but, in a political and administrative point of view, the whole continental territory of the Roman state from the Straits to the Alps including the Illyrian possessions - burgess, Latin, and non-Italian communities without exception--was in the ordinary course of things under the administration of the supreme magistrates who were acting in Rome, as in fact her colonial foundations extended through all this territory. According to Sulla's arrangement Italy proper, the northern boundary of which was at the same time changed from the Aesis to the Rubico, was - as a region now inhabited without exception by Roman citizens - made subject to the ordinary Roman authorities; and it became one of the fundamental principles of Roman state-law, that no troops and no commandant should ordinarily be stationed in this district. The Celtic country south of the Alps on the other hand, in which a military command could not be dispensed with on account of the continued incursions of the Alpine tribes, was constituted a distinct governorship after the model of the older transmarine commands[27].