Among the slaves of the king was a young boy named Servius Tullius. One day the lad fell fast asleep in the doorway of the palace.
As he slept, it chanced that Tanaquil, the queen, came out to walk in the palace grounds. When she saw Servius she would have roused him, save that a flame of fire was playing around his head, yet doing him no hurt.
But the attendants of the queen also saw this strange sight, and at once rushed off in search of water with which to put out the flame.
Tanaquil, however, called to them to return, saying: "Leave the lad to sleep. The flame will not injure him."
Then, hastening back to the palace, she told the king what she had seen, adding: "The gods have appointed Servius to great honour."
From that day the boy was no longer treated as a slave, but as the king's son, and when he was older he was married to the daughter of Tarquinius.
Little by little Servius Tullius was entrusted with the cares of State, while the Senate or elders of the people treated him as a prince.
Now the sons of Ancus, from whom Tarquinius had stolen the crown, were indignant when they saw the former slave treated with more honour than were they, and they grew afraid lest the king should appoint Servius to succeed him. That this might not be, they determined to kill Tarquinius.
Hiring two men, they bade them go kill the king, and they should be well rewarded for their deed.
So the men disguised themselves as shepherds, and begged to be admitted to the presence of Tarquinius, that he might settle their dispute, for, so they pretended, they had quarrelled with one another while they tended their flocks.
When they stood before the king one of the shepherds began to tell a piteous tale. While Tarquinius was listening, the other suddenly raised his axe, and with one great blow killed the king. The false shepherds then fled from the palace.
But the sons of Ancus had forgotten that Tanaquil was left to thwart their plans.
No sooner was the king slain, than she ordered the doors of the palace to be closed. Then, when the people heard it rumoured that the king was dead and rushed to the palace, Tanaquil opened an upper window and spoke to the crowds below.
"The king is but wounded," she told them, "he is not dead. He has commanded that you should obey Servius until he is again able to rule." But all the while Tarquinius lay in the palace, dead.
But the people, loyal, as they thought, to the wishes of their king, allowed Servius to rule. And the sons of Ancus knew that they had killed the king in vain.
A few days later it was known that the king was really dead; yet, although neither the Senate nor the people had chosen Servius to be king, he continued to sit upon the throne and to rule over Rome. Moreover, he was wise enough to try to win the hearts of the people by promising to give them land and to rule justly.
So well did he perform his royal duties, that when he called together an assembly of the people he was at once elected king.