Legatus in the context of "Julius Caesar"

During the classical period, the Roman Empire controlled the Mediterranean and much of Europe, Western Asia, and North Africa. The Romans conquered most of these territories in the time of the Republic, and it was ruled by emperors following Octavian's assumption of power in 27 BC. Over the 4th century AD, the empire split into western and eastern halves. The western empire collapsed in 476 AD, while the eastern empire endured until the fall of Constantinople in 1453.

By 100 BC, the city of Rome had expanded its rule from the Italian peninsula to most of the Mediterranean and beyond. However, it was severely destabilised by civil wars and political conflicts, which culminated in the victory of Octavian over Mark Antony and Cleopatra at the Battle of Actium in 31 BC, and the subsequent conquest of the Ptolemaic Kingdom in Egypt. In 27 BC, the Roman Senate granted Octavian overarching military power (imperium) and the new title of Augustus, marking his accession as the first Roman emperor. The vast Roman territories were organized into senatorial provinces, governed by proconsuls who were appointed by lot annually, and imperial provinces, which belonged to the emperor but were governed by legates.

Vespasian (/vɛsˈpeɪʒ(i)ən, -ziən/; Latin: Vespasianus [wɛspasjˈaːnus]; 17 November AD 9 – 23 June 79) was Roman emperor from 69 to 79. The last emperor to reign in the Year of the Four Emperors, he founded the Flavian dynasty, which ruled the empire for 27 years. His fiscal reforms and consolidation of the empire brought political stability and a vast building program.

Vespasian was the first emperor from an equestrian family who rose only later in his lifetime into the senatorial rank as the first of his family to do so. He rose to prominence through military achievement: he served as legate of Legio II Augusta during the Roman invasion of Britain in 43, and later led the suppression of the Jewish rebellion of 66–70.

A military tribune (from Latin tribunus militum 'tribune of the soldiers') was an officer of the Roman army who ranked below the legate and above the praefectus castrorum (a centurion). Young men of Equestrian rank often served as military tribunes as a stepping stone to the Senate. The tribunus militum should not be confused with the elected political office of tribune of the people (tribunus plebis) nor with that of tribunus militum consulari potestate.

Tribune (Latin: Tribunus) was the title of various elected officials in ancient Rome. The two most important were the tribunes of the plebs and the military tribunes. For most of Roman history, a college of ten tribunes of the plebs acted as a check on the authority of the senate and the annual magistrates, holding the power of ius intercessionis to intervene on behalf of the plebeians, and veto unfavourable legislation. There were also military tribunes, who commanded portions of the Roman army, subordinate to higher magistrates, such as the consuls and praetors, promagistrates, and their legates. Various officers within the Roman army were also known as tribunes. The title was also used for several other positions and classes in the course of Roman history.

A papal legate or apostolic legate (from the ancient Roman title legatus) is a personal representative of the Pope to foreign nations, to some other part of the Catholic Church, or to representatives of a state or monarchy. A legate is empowered in matters of Catholic faith and for the settlement of ecclesiastical matters.

The legate is appointed directly by the Pope—the Bishop of Rome and head of the Catholic Church. Hence a legate is usually sent to a government, to a sovereign, to a large body of believers (such as a national church), or to take charge of a major religious effort, such as an ecumenical council, a crusade to the Holy Land, or even against a heresy such as the Cathars.

The praefectus castrorum ("camp prefect") was, in the Roman army of the early Empire, the third most senior staff officer of the Roman legion after the legate (legatus; the commanding officer) and the senior military tribune (tribunus laticlavius; the executive officer), both of whom were from the senatorial class.

The camp prefect was the senior enlisted advisor at a command and quartermaster; responsible for military logistics and requisition (training, equipment procurement and maintenance, and construction of the camp, etc.), acting liaison between the legate and the centurions, but could command the legion whenever the senior commanders were absent. The post was usually held by a soldier promoted from the centurionate, having already served as a chief centurion (primus pilus) of a legion, and was therefore open to ordinary, plebeian citizens. Prefects of this rank, for example Sextus Vibius Gallus, were awarded prizes (dona) to mark their achievements.