The writings of Marcus Tullius Cicero constitute one of the most renowned collections of historical and philosophical work in all of classical antiquity. Cicero was a Roman politician, lawyer, orator, political theorist, philosopher, and constitutionalist who lived during the years of 106–43 BC. He held the positions of Roman senator and Roman consul (chief-magistrate) and played a critical role in the transformation of the Roman Republic into the Roman Empire. He was extant during the rule of prominent Roman politicians, such as those of Julius Caesar, Pompey, and Marc Antony. Cicero is widely considered one of Rome's greatest orators and prose stylists.
Cicero is generally held to be one of the most versatile minds of ancient Rome. He introduced the Romans to the chief schools of Greek philosophy, and also created a Latin philosophical vocabulary; distinguishing himself as a linguist, translator, and philosopher. A distinguished orator and successful lawyer, Cicero likely valued his political career as his most important achievement. Today he is appreciated primarily for his humanism and philosophical and political writings. His voluminous correspondence, much of it addressed to his friend Atticus, has been especially influential, introducing the art of refined letter writing to European culture. Cornelius Nepos, the 1st-century BC biographer of Atticus, remarked that Cicero's letters to Atticus contained such a wealth of detail "concerning the inclinations of leading men, the faults of the generals, and the revolutions in the government" that their reader had little need for a history of the period.