From the Founding of the City/Book 18

[Y.R. 496. B.C. 256.] Attilius Regulus, consul, having overcome the Carthaginians in a sea-fight, passes over into Africa: kills a serpent of prodigious magnitude, with great loss of his own men. [Y.R. 497. B.C. 255.] The senate, on account of his successful conduct of the war, not appointing him a successor, he writes to them, complaining; and, among other reasons for desiring to be recalled, alledges, that his little farm, being all his subsistence, was going to ruin, owing to the mismanagement of hired stewards. [Y.R. 498. B.C. 254.] A memorable instance of the instability of fortune exhibited in the person of Regulus, who is overcome in battle, and taken prisoner by Xanthippus, a Lacedaemonian general. [Y. R. 499. B. C. 253.] The Roman fleet shipwrecked; which disaster entirely reverses the good fortune which had hitherto attended their affairs. Titus Corucanius, the first high priest chosen from among the commons. [Y. R. 500. B. C. 252.] P. Sempronius Sophus and M. Yalerius Maximus, censors, examine into the state of the senate, and expel thirteen of the members of that body. [Y. R. 501. B. C. 251.] They hold a lustrum, and find the number of citizens to be two hundred and ninety-seven thousand seven hundred and ninety-seven. [Y. R. 502. B. C. 250.] Regulus being sent by the Carthaginians to Rome to treat for peace, and an exchange of prisoners, binds himself by oath to return if these objects be not attained; dissuades the senate from agreeing to the propositions: and then, in observance of his oath, returning to Carthage, is put to death by torture.

Ab Urbe Condita - Periochae/liber XVIII