Appian

Appian began writing his history around the middle of the second century AD. Only sections from half of the original 24 books survive today of a much larger history known as The Roman History. The section of this history known as The Civil Wars comprises books 13–17 of the original 24 of the Roman History. This history narrates the history of the Romans from the time of the Gracchan tribunates, through the civil wars of Marius, Sulla, Caesar and Pompey, to break off in the time of the Second Triumvirate. These five books stand out because they are one of the few comprehensive histories available on the transition of the Roman state from Republic to Empire and the ensuing civil and military strife.

Besides Appian, this period is also covered by a handful of ancient authors with varying degrees of detail and viewpoints. The commentaries of Julius Caesar record his personal, mainly military, observations of the Gallic Wars. Plutarch's Roman biographies sketch the lives of the major leaders of the late Republican period, recording events Plutarch thought interesting and give only a perfunctory explanation of historic events. The Roman author Velleius' history examines Roman history from the city's foundation until AD 29. This history is more detailed in the late Republic and early Empire period, while the earlier history is condensed. The Epitome of Roman History by Florus, also covers Roman history from mythical times until the 5th century AD in an extremely condensed format. The history of Diodorus of Sicily also covers Roman history until the Gallic Wars, but his history becomes fragmentary after around 300 BC.

Another work of Appian's history which still survives mostly extant is called The Foreign Wars. This history describes the wars the Romans fought against other cultures throughout their history. The mostly extant work narrates the wars in Spain, the Punic Wars in both Italy and Africa, the wars against the Seleucid Empire, and the Mithridatic Wars. Several small fragments also survive, describing the wars against the Samnites, Illyrians, Macedonians, Numidians, and the Gauls. Especially notable is this work's ethnographic structure. Appian most likely used this structure to facilitate his readers' orientation through the sequence of events, which are united only by their relationship to Rome. For example, the chapter on Spain recounts Roman history in Spain chronologically with the Romans' first intervention in Spain during the War with Hannibal. The book goes on to describe the Roman conquest of several regions of Spain, followed by their wars with Spanish tribes and the Numantine War. The chapter on Spain concludes with the war against Sertorius in roughly 61 BC. Likewise, the chapter on the Hannibalic wars only recounts the battles that took place on the Italian Peninsula during the second Punic war, while the chapters on the Punic War recount all the action that occurred in northern Africa during the first and second Punic war.

One might expect that a historical work covering nine centuries and countless different peoples would involve a multitude of sources from different periods. However, Appian's sources remain uncertain, as he only mentions the source of his information under special circumstances. He may have relied primarily on one author for each book, whom he did not follow uncritically, since Appian also used additional sources for precision and correction. At our present state of knowledge questions regarding Appian's sources cannot be resolved.

• William Smith (ed.) (1870), Dictionary of Greek and Roman Biography and Mythology, Vol. 1, pp. 247–248