"A Study of History" is an extensive 12-volume universal history, exploring the development and decay of world civilizations throughout the ages. The author proposes that civilizations rise and fall based on their responses to challenges, both physical and social. The book also puts forth the idea that religions play a crucial role in the rise of civilizations and that the failure of a civilization's creative power can lead to its decline. The work is renowned for its scholarly depth and its controversial theories about the cyclical nature of history.

"Lives of the Caesars" is a historical narrative that provides a detailed account of the personal and public lives of the first twelve Roman emperors, from Julius Caesar to Domitian. The author presents a vivid depiction of their character, behavior, appearance, and private lives, as well as their political actions, military exploits, and administrative policies. The book is a valuable source of information about the Roman Empire's early days, offering a unique perspective on the power, corruption, and extravagance of the Roman elite.

"The Histories" is a comprehensive account of the rise of the Roman Empire, focusing on the period from 264-146 BC. The author, a Greek statesman, provides a detailed analysis of the political, military, and social structures of Rome, attributing its success to a balanced constitution and superior military organization. The work also includes first-hand accounts of several significant events, such as the Third Punic War and the Numantine War.

This book is a combination of three works by a Roman historian and politician, focusing on the political and military events of the late Roman Republic. It first covers the conspiracy led by Catiline in 63 BC, then shifts to the war against Jugurtha in North Africa, and finally provides a fragmentary history of Rome from 78-67 BC. The author uses these events to critique the moral decay of Rome, highlighting the corruption, greed, and ambition that he believed led to the fall of the Republic.