After the death of Romulus, Rome struggles to find a new king:
Once all of this had happened regarding Romulus, it seemed right to everyone that there should continue to be a monarchy, but strife and discord arose among those in Rome not just about who, individually, should be the king, but about whether he should be Roman or Sabine. To those first men who founded the city with Romulus, it seemed unbearable that the Sabines, who had come to the city after them, should take it in hand to rule. The Sabines thought, on the contrary, that since Romulus ruled by himself after the death of Titus Tatius, it was right that the new king should be selected from among themselves.
Both parties thus contended against each other. Since the state was thus held in suspense on this matter, the Patricians, being then 150 in number, established that each one of them would, in turns, dress himself in the royal outfit and both sacrifice to the gods and give orders to the state for six hours of the night and six hours of the day. This apportionment of parts equally among each patrician seemed to hold up well, even to the citizens who were ruled by the system. The rapid exchange of power tended to dispel enmity, since even subjects could see that the same day and night elevated a man from a private station to regal dignity, and then returned him to private life. I know some other things which are said about this sort of rule, but I myself have trusted the most plausible account. This scheme of rule is called by the Romans mesobasileia.
Τούτων δὲ περὶ τὸν ῾Ρωμύλον συμβεβηκότων βασιλεύεσθαι μὲν ἐδόκει πᾶσιν, ἔρις δέ τις καὶ στάσις ἐφύετο τοῖς ἐν ῾Ρώμῃ οὐχ ὑπὲρ ἀνδρὸς μόνον ἡγεμονεύσοντος, ἀλλὰ καὶ πότερον τῶν γενῶν παρέξει τὸν ἄρξοντα. τοῖς τε γὰρ μετὰ ῾Ρωμύλου πρώτοις συνοικίσασι τὴν πόλιν οὐκ ἀνεκτὸν ἐδόκει παρ’ αὐτῶν προσληφθέντας τοὺς Σαβίνους εἰς πολιτείαν ἄρχειν τῶν δεξαμένων βιάζεσθαι· οἱ Σαβῖνοι δὲ ἑτέρωθεν, ὅτι τοῦ Τατίου θανόντος μόνον εἴασαν τὸν ῾Ρωμύλον ἄρχειν, ἐξ ἑαυτῶν ἠξίουν αἱρεθῆναι τὸν ἄρξοντα.
῎Ηριζον μὲν οὖν οὕτω τὰ μέρη ἑκάτερα, μετεώρου δ’ ἐπὶ τούτοις ὄντος τοῦ πολιτεύματος οἱ πατρίκιοι πεντήκοντα καὶ ἑκατὸν ὄντες ἔταξαν ἕκαστον ἐν μέρει τοῖς βασιλικοῖς παρασήμοις κοσμούμενον θύειν τε τοῖς θεοῖς καὶ χρηματίζειν, ἓξ μὲν τῆς νυκτὸς ὥρας, ἓξ δὲ τῆς ἡμέρας. ἡ γὰρ διανομὴ τῶν καιρῶν κατὰ τὸ ἴσον ἑκάστου καὶ πρὸς τοὺς ἄρχοντας καλῶς ἔχειν ἐδόκει καὶ πρὸς τοὺς ἀρχομένους αὐτούς· ἀφῄρει γὰρ τὸν φθόνον ἡ ταχίστη τῆς ἐξουσίας ἀπόθεσις, ὁρώντων τῶν ἀρχομένων τῆς αὐτῆς ἡμέρας τε καὶ νυκτὸς τὸν αὐτὸν ἰδιώτην ἐκ βασιλέως γινόμενον. οἶδα μὲν οὖν καὶ ἕτερά τινα περὶ τῆς τοιαύτης εἰρημένα ἀρχῆς, ἀλλ’ αὐτὸς τῷ πιθανωτέρῳ ἐθέμην. τὸ δὲ σχῆμα τῆς ἀρχῆς τοῦτο μεσοβασιλεία ῾Ρωμαίοις ὠνόμαστο.