This source is an excerpt from book XVIII of Polybius’ The Histories. Consisting of over 40 volumes, The Histories was likely written in the latter half of his life, which spanned almost 80 years. Many of the events described in Polybius’ volumes were written contemporaneously with the rise of imperial, republican Rome providing insight into the events and thinking of the time. This particular excerpt describes the battle tactics of the Romans as opposed to the Macedonians of Alexander. While it is likely that the average student of history is familiar with the wars and battles of Rome, such as the Punic Wars, very little attention is paid to the strategy and tactics of the Roman army. As Polybius asks, “Why is it then that the Romans conquer?”