Decemviri (singular decemvir) is a Latin term meaning "Ten Men" which designates any such commission in the Roman Republic (cf. Triumviri, Three Men). Different types of decemvirate include the writing of laws with consular imperium (legibvs scribvndis consvlari imperio), the judging of litigation (stlitibvs ivdicandis), the making of sacrifices (sacris facivndis), and the distribution of public lands (agris dandis adsignandis).

In 452 BC the plebeians and patricians of Rome agreed to the appointment of a commission of ten men to write up a code of law defining the principles of Roman administration; during the decemviri's term in office, all other magistracies would be suspended, and their decisions were not subject to appeal. The first set of decemviri, composed entirely of patricians, assumed office in 451 BC, and was led by Appius Claudius Crassus and Titus Genucius Augurinus, who were consuls for that year. Each decemvir administered the government for one day in turn, and whichever decemvir presided on any given day was preceded by the twelve lictors bearing the fasces; none of the other decemviri received any protection from the lictors. Their administration of justice was exemplary and they submitted to the Comitia Centuriata a code of laws in ten headings, which was passed.

Gaius Julius Caesar (Classical Latin: [ˈɡaː.i.ʊs ˈjuː.lɪ.ʊs ˈkaj.sar], July 100 BC – 15 March 44 BC) was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire.

In 60 BC, Caesar, Crassus and Pompey formed a political alliance that was to dominate Roman politics for several years. Their attempts to amass power through populist tactics were opposed by the conservative elite within the Roman Senate^{[citation needed]}, among them Cato the Younger with the frequent support of Cicero. Caesar's conquest of Gaul, completed by 51 BC, extended Rome's territory to the English Channel and the Rhine. Caesar became the first Roman general to cross both when he built a bridge across the Rhine and conducted the first invasion of Britain.

These achievements granted him unmatched military power and threatened to eclipse Pompey's standing. The balance of power was further upset by the death of Crassus in 53 BC. Political realignments in Rome finally led to a standoff between Caesar and Pompey, the latter having taken up the cause of the Senate. Ordered by the Senate to stand trial in Rome for various charges, Caesar marched on Rome with one legion—legio XIII—from Gaul to Italy, crossing the Rubicon in 49 BC. This sparked a civil war from which he emerged as the unrivaled leader of the Roman world.