C. Sallustius Crispus, more commonly known as Sallust, was a Roman historian of the 1st century BC, born c. 86 in the Sabine community of Amiternum. There is some evidence that Sallust's family belonged to a local aristocracy, but we do know that he did not belong to Rome's ruling class. Thus he embarked on a political career as a "novus homo," serving as a military tribune in the 60s, quaestor from 55 to 54, and tribune of the plebs in 52. Sallust was expelled from the senate in 50 on moral grounds, but quickly revived his career by attaching himself to Julius Caesar. He served as quaestor again in 48, as praetor in 46, and governed the new province in the former Numidian territory until 44. Sallust's political career ended upon his return to Rome and Caesar's assassination in 44.

We possess in full two of the historical works that have been convincingly ascribed to Sallust, the monographs, Bellum Catilinae and Bellum Jugurthinum. We have only fragments of the third work, the Historiae. There is less agreement about the authorship of some other works that have, at times, been attributed to him. In Bellum Catilinae, Sallust outlines the conspiracy of Catiline, a brash and ambitious patrician who tried to seize power in Rome in 63 BC. In his other monograph, Sallust used the Jugurthine War as a backdrop for his examination of the development of party struggles in Rome in the 1st century. The Historiae describe in general the history of the years 78-67 BC.

Although Sallust's purposes in writing have been debated over the years, it seems logical to classify him as a senatorial historian who adopted the attitude of a censor. The historical details outlined in his monographs serve as paradigms for Sallust. In Bellum Catilinae, Sallust uses the figure of Catiline as a symbol of the corrupt Roman nobility. Indeed, much of what Sallust writes in this work does not even concern Catiline. The content of Bellum Jugurthinum also suggests that Sallust was more interested in character studies (e.g. Marius) than the details of the war itself. With respect to writing style, the main influences on Sallust's work were Thucydides and Cato the Elder. Evidence of the former's influence includes emphasis on politics, use of archaisms, character analysis, and selective omission of details. The use of such devices as asyndeton, anaphora, and chiasmus reflect preference for the old-fashioned Latin style of Cato to the Ciceronian periodic structure of his own era.

Whether Sallust is considered a reliable source or not, he is largely responsible for our current image of Rome in the late republic. He doubtless incorporates elements of exaggeration in his works and has at times been described as more of an artist or politician than historian. But our understanding of the moral and ethical realities of Rome in the 1st century BC would be much weaker if Sallust's works did not survive.

On the whole, antiquity looked favourably on Sallust as an historian. Tacitus speaks highly of him (Annals, iii. 30); and Quintilian does not hesitate to put him on a level with Thucydides (x.1), and declares that he is a greater historian than Livy (ii.5).

Sallust struck out for himself practically a new line in literature, his predecessors having functioned as little better than mere dry-as-dust chroniclers, whereas he endeavored to explain the connection and meaning of events and successfully delineated character. The contrast between his early life and the high moral tone adopted by him in his writings has frequently made him a subject of reproach, but history gives no reason why he should not have reformed.

In any case, his knowledge of his own former weaknesses may have led him to take a pessimistic view of the morality of his fellow-men, and to judge them severely. He took as his model Thucydides, whom he imitated in his truthfulness and impartiality, in the introduction of philosophizing reflections and speeches, and in the brevity of his style, sometimes bordering upon obscurity. Some readers have ridiculed his fondness for old words and phrases (in which he imitated Cato the Elder) as an affectation, but this very affectation and his rhetorical exaggerations made Sallust a favorite author in the 2nd century and later.

Nietzsche credits Sallust in Twilight of the Idol for his epigrammatic style: "My sense of style, for the epigram as a style, was awakened almost instantly when I came into contact with Sallust" and praises him for being "compact, severe, with as much substance as possible, a cold sarcasm against 'beautiful words' and 'beautiful sentiments'."