Although he was a Greek by birth, Plutarch wrote in a world ruled by Rome and strongly influenced by Roman values. For this reason, the predecessors to Ten Famous Lives are not Greek biographical works, such as the dialogues of Plato and Xenophon, but the biographical passages of such Roman historians as Sallust and Livy. Sallust and Livy took a strongly didactic tone in their works, presenting the lives of famous Romans as moral examples to be imitated and the lives of notorious Romans as negative examples to be avoided. This use of biography to provide ethical instruction is common throughout most of Roman literature and may even be seen in the works of poets such as Vergil and Horace. It is not surprising, therefore, to find the influence of this type of literature reaching even as far as the Greek city of Chaeronea, where Plutarch lived and worked.
Yet none of these Roman authors had written as extensive a series of biographies as Plutarch. Sallust, for instance, conceived his Conspiracy of Catiline (4342 b.c.e.) and History of the Jugurthine War (4140 b.c.e.) as historical monographs rather than as true biographies; while they contain a number of biographical details, their focus remains a historical event rather than the individual responsible for that event. Plutarch reversed this perspective and recorded historical occurrences for what they revealed about the characters of the individuals involved. For this reason, Plutarch may be regarded as the inventor of biography in the modern sense.