Titus Livius (Livy), The History of Rome, Book 1
D. Spillan, A.M., M.D., Ed.

17. Meanwhile ambition and contention for the throne actuated the minds of the fathers; factions had not yet sprung up from individuals, because, among a new people, no one person was eminently distinguished above the rest: the contest was carried on between the different orders. [2] The descendants of the Sabines wished a king to be elected [p. 24]out of their body, lest, because there had been no king on their side since the death of Tatius, they might lose their claim to the crown¹ according to the compact of equal participation. The old Romans spurned the idea of a foreign prince. [3] Amid this diversity of views, however, all were anxious that there should be a king, they not having yet tasted the sweets of liberty. [4] Fear then seized the senators, lest the minds of the surrounding states being incensed against them, some foreign power should attack the state, now without a government, and the army without a leader. It was therefore their wish that there should be some head, but no one could bring himself to give way to another. [5] Thus the hundred senators divide the government among them, ten decuries being formed, and one selected from each decury, who was to have the chief direction of affairs. [6] Ten governed; one only was attended with the insignia of authority and the lictors: their power was limited to the space of five days, and it passed through all in rotation, and the interval between a kingly government lasted a year. From the circumstance it was called an Interregnum, a term which holds good even now. [7] But the people began to murmur, that their slavery was multiplied, and that they had got a hundred sovereigns instead of one, and they seemed determined to bear no authority but that of a king, and that one of their own choosing. [8] When the fathers perceived that such schemes were in agitation, thinking it advisable to offer them, of their own accord, what they were sure to lose; they thus conciliate the favour of the people by yielding to them the supreme power, yet in such a manner as to grant them no greater privilege than they reserved to themselves. [9] For they decreed, that when the people should choose a king, the election should be valid, if the senate approved. And² the same forms are observed at this day in passing laws and electing magistrates, though their efficacy has been taken away; for before the people begin to vote, the senators declare their approbation, whilst the result of the elections is still uncertain. [10] [p. 25]Then the interrex, having called an assembly of the people, addressed them in this manner: “Do you, Romans, choose yourselves a king, and may it prove fortunate, happy, and auspicious to you; so the fathers have determined. [11] Then, if you choose a prince worthy to succeed Romulus, the fathers will confirm your choice.” This concession was so pleasing to the people, that, not to be outdone in generosity, they only voted, and required that the senate should determine who should be king of Rome.