After Caesar beats the Republicans in Africa, Cato takes his own life at Utica. Plutarch says the first wound was not enough and he tore it open again.
But when Butas had gone out, Cato drew his sword from its sheath and stabbed himself below the breast.
By choosing death over Caesar's pardon, Cato made himself a martyr for and a symbol of the Republic. Eulogies by Cicero and Brutus began to present him as a great Stoic philosopher.
Based on Wikipedia: Cato the Younger
he chose to take his own life rather than accept what he saw as Caesar's tyrannical pardon, turning himself into a martyr for and a symbol of the Republic
Cato's death triggered a series of eulogies, of which both Cicero and Brutus were authors, starting to identify Cato as a great Stoic philosopher.