Titus Livius (Livy), The History of Rome, Book 1
Benjamin Oliver Foster, Ph.D., Ed.

45. When the king had promoted the grandeur of the state by enlarging the City, and had shaped all his domestic policy to suit the demands of peace as well as those of war, he was unwilling that arms should always be the means employed for strengthening Rome's power, and sought to increase her sway by diplomacy, and at the same time to add something to the splendour of the City. [2] Even at that early date the temple of Diana at Ephesus enjoyed great renown. It was reputed to have been built through the cooperation of the cities of Asia, and this harmony and community of worship Servius praised in superlative terms to the Latin nobles, with whom, both officially and in private, he had taken pains to establish a footing of hospitality and friendship. [3] By dint of reiterating the same arguments he finally carried his point, and a shrine of Diana was built in Rome by the nations of Latium conjointly with the Roman People. This was an admission that Rome was the capital —a point which had so often been disputed [p. 159]with force of arms. But though it seemed that the¹ Latins had lost all interest in this contention after the repeated failure of their appeals to war, there was one man amongst the Sabines who thought that he saw an opportunity to recover the empire by a shrewd plan of his own. [4] In the Sabine country, on the farm of a certain head of a family, there was born a heifer of extraordinary size and beauty; [5] a marvel to which the horns afterwards bore testimony, for they were fastened up for many generations in the vestibule of Diana's temple. [6] This heifer was regarded as a prodigy, as indeed it was; soothsayers prophesied that the state whose citizens should sacrifice the animal to Diana would be the seat of empire, and this prediction had reached the ears of the priest of Diana's shrine. On the earliest day which seemed suitable for the sacrifice, the Sabine drove the heifer to Rome, and bringing her to the shrine of Diana, led her up to the altar. There the Roman priest, moved by the great size of the victim, which had been much talked of, and recalling the prophecy, asked the Sabine, “What is this that you are doing, stranger? Would you sacrifice, unpurified, to Diana? Not so! First bathe in a running stream; the Tiber flows by in the bottom of the valley.” [7] The stranger, touched by a scruple and wishing to do everything according to ritual, that the prodigy might be answered by the event, at once descended to the Tiber. Meanwhile the Roman offered the heifer to Diana, an act which was exceedingly acceptable to the king and the citizens.