The Rise of the Roman Empire

In 168 BCE, the ancient Greek calvary officer and historian Polybius was arrested along with 1,000 other Achaeans and held as a prisoner for 16 years. Rome had conquered the major Greek cities and taken a privileged position of power. Greece had fallen, and Rome was the political star. Although many of his compatriots were imprisoned or killed, Polybius was well-connected, and his privileged life allowed him to live out his sentence as a mentor, advisor, and scholar for the Roman elite. He used his access to Roman officials and his freedom to travel as the foundation for his research, thereby giving birth to a new way of thinking about political and social power.

Polybius was not the first to examine history through a critical lens. Herodotus examined the Greco-Persian War in his Histories. Thucydides studied the Peloponnesian War, seeking insight into human nature. Plato’s Republic blended philosophy and historical analysis. Aristotle’s Politics outlined different forms of government and their corrupt counterparts. However, Polybius’s approach in Histories, a collection of 40 volumes covering 264 BCE to the end of 146 BCE (of which only five volumes remain), was entirely new. He dedicated himself to a specific question: How did the Roman Republic become so powerful?

The Greek writer devoted himself to a historical critique of the Roman government’s military, political, and social maneuverings. He saw historical analysis as the key to understanding how these systems work together and to improving the future: “Certainly mankind possesses no better guide to conduct than the knowledge of the past” (41). Unlike his predecessors, Polybius set myth aside and focused on an empirical study of Roman history. He limited his focus both in time frame and scale, centering his cause/effect analysis on Roman political systems over a century.

While previous historical analyses incorporated mythology and philosophy, Polybius established a critical tradition by restricting himself to empirical evidence. Approaching his topic from a position of causality allowed Polybius to identify how human behavior plays a role in political systems and historical cycles. By laying out all the facts and seeking patterns, he was able to spot patterns and make meaning from them. This technique is the foundation for contemporary research. For example, qualitative researchers use axial coding—the process of identifying recurring codes, patterns, and relationships—to find meaning in complex data. Polybius’s commitment to causal analysis and pattern recognition laid the foundation for modern comparative political science and historiography, influencing thinkers who sought to understand how human behavior shapes institutions.

Polybius’s unique approach continues to be admired by philosophers and researchers. Historian Sempronius Asellio, Cicero, Diodorus, Plutarch, and many others utilized Polybius’s works and techniques in their texts. 16th- century philosopher and diplomat Niccolò Machiavelli also cited Polybius as an inspiration for his work The Discourses. Edward Gibbon adopted Polybius’s cause/effect model in his comprehensive work The Decline and Fall of the Roman Empire. Polybius thus created a framework for thinking about the past that continues to shape the future. Approaching his topic from a position of causality and empirical observation, the Greek historian not only provided a model for future historians but also demonstrated how political cycles could be anticipated—an approach that continues to shape political theory and historical critique today.