Sextus Iulius Frontinus, vir consularis de re militari

...thought it best to kill the princes of Gabii. Because he did not want this to be known to anyone, he gave no answer to the messenger who had been sent to him by his son. However, when he happened to be walking in his garden, he struck off the heads of the tallest poppies. The messenger returned without an answer and reported to the young Tarquinius what he had seen his father doing. He understood that the same thing had to be done to the prominent men. Caesar, who suspected the loyalty of the Egyptians, wanted to appear devoted to their customs and life under the guise of security, the inspection of the city and works, and at the same time, more unrestrained banquets. He pretended that he was captivated by the grace of the place, but during this dissimulation, he prepared his reserves and occupied Egypt. Ventidius, in the Parthian war against King Pacorus, was not unaware that a certain Pharneus, a Tyrian by nationality, was reporting everything that was being done among his own people to the Parthians, as he appeared to be an ally. Ventidius converted the barbarian's treachery to his own advantage. For he pretended to fear that the things he most wanted to happen would occur, and pretended to hope for the things he feared. Anxious, therefore, that the Parthians would cross the Euphrates before his own legions—which he held in Cappadocia beyond the Taurus—could arrive, he dealt studiously with the traitor. He persuaded him, through his habitual treachery, to convince the Parthians to cross the army at Zeugma, where the path is shortest and the Euphrates leaves its channel. For he asserted that if they came elsewhere, he would use the convenience of the hills to elude their archers, but he feared everything if they should throw themselves into the open fields. Led by this affirmation, the barbarians brought their army by a longer, circuitous route. While they joined the wider banks and consequently more laborious bridges, and set up their instruments, they spent more than forty days. In this space of time, Ventidius used the time to gather his forces. Three days before the Parthian arrived, having received his troops, he joined battle, defeated the Parthians, and killed them. Mythridates, while Pompey was besieging him, planning his flight for the next day, in order to obscure this plan, grazed his cattle more widely and even up to the valleys adjacent to the enemy. He also arranged meetings with many people for the sake of diverting suspicion. He ordered more fires than usual to be made throughout the camp. Then, at the second watch, he led his column through the enemy's own camp. The Emperor Caesar Domitianus Augustus Germanicus, when he wished to crush the Germans who were under arms, and did not ignore that they would undertake a greater war effort if they sensed the arrival of such a great leader, concealed his departure from the Gauls. By doing so, he fell upon them in an unexpected war and crushed the ferocity of those huge nations, providing for the provinces. Claudius Nero, when he desired to kill Hasdrubal and his forces before they could join his brother Hannibal...