They had occupied the islands not on their own account, but for the security of Italy.

Now that the confederacy possessed the three large islands, it might call the Tyrrhene Sea its own.
Method of Administration in the Transmarine Possessions Provincial Praetors The acquisition of the islands in the western sea of Italy introduced into the state administration of Rome a distinction, which to all appearance originated in mere considerations of convenience and almost accidentally, but nevertheless came to be of the deepest importance for all time following--the distinction between the continental and transmarine forms of administration, or to use the appellations afterwards current, the distinction between Italy and the provinces.
Hitherto the two chief magistrates of the community, the consuls, had not had any legally defined sphere of action; on the contrary their official field extended as far as the Roman government itself.

Of course, however, in practice they made a division of functions between them, and of course also they were bound in every particular department of their duties by the enactments existing in regard to it; the jurisdiction, for instance, over Roman citizens had in every case to be left to the praetor, and in the Latin and other autonomous communities the existing treaties had to be respected.

The four quaestors who had been since 487 distributed throughout Italy did not, formally at least, restrict the consular authority, for in Italy, just as in Rome, they were regarded simply as auxiliary magistrates dependent on the consuls.

This mode of administration appears to have been at first extended also to the territories taken from Carthage, and Sicily and Sardinia to have been governed for some years by quaestors under the superintendence of the consuls; but the Romans must very soon have become practically convinced that it was indispensable to have superior magistrates specially appointed for the transmarine regions.