Roman history in the context of "Origines"

Trajan (/ˈtreɪdʒən/ TRAY-jən; born Marcus Ulpius Traianus, 18 September 53 – c. 9 August 117) was a Roman emperor from AD 98 to 117, remembered as the second of the Five Good Emperors of the Nerva–Antonine dynasty. He was a philanthropic ruler and a successful soldier-emperor who presided over one of the greatest military expansions in Roman history, during which, by the time of his death, the Roman Empire reached its maximum territorial extent. He was given the title of Optimus ('the best') by the Roman Senate.

Trajan was born in the municipium of Italica in the present-day Andalusian province of Seville in southern Spain, an Italic settlement in Hispania Baetica; his gens Ulpia came from the town of Tuder in the Umbria region of central Italy. His namesake father, Marcus Ulpius Traianus, was a general and distinguished senator. Trajan rose to prominence during the reign of Domitian; in AD 89, serving as a legatus legionis in Hispania Tarraconensis, he supported the emperor against a revolt on the Rhine led by Antonius Saturninus. He then served as governor of Germania and Pannonia. In September 96, Domitian was succeeded by the elderly and childless Nerva, who proved to be unpopular with the army. After a revolt by members of the Praetorian Guard, Nerva decided to adopt as his heir and successor the more popular Trajan, who had distinguished himself in military campaigns against Germanic tribes.

The king of Rome (Latin: Rex Romae) was the ruler of the Roman Kingdom, a legendary period of Roman history that functioned as an elective monarchy. According to legend, the first king of Rome was Romulus, who founded the city in 753 BC upon the Palatine Hill. Seven legendary kings are said to have ruled Rome until 509 BC, when the last king was overthrown. These kings ruled for an average of 35 years.

The kings after Romulus were not known to be dynasts and no reference is made to the hereditary principle until after the fifth king Tarquinius Priscus. Consequently, some have assumed that the Tarquins' attempt to institute a hereditary monarchy over this conjectured earlier elective monarchy resulted in the formation of the Republic.

Roman currency for most of Roman history consisted of gold, silver, bronze, orichalcum (brass), and copper coinage. From its introduction during the Republic, in the third century BC, through Imperial times, Roman currency saw many changes in form, denomination, and composition. A feature was the inflationary debasement and replacement of coins over the centuries. Notable examples of this followed the reforms of Diocletian. This trend continued with Byzantine currency.

Due to the economic power and longevity of the Roman state, Roman currency was widely used throughout western Eurasia and northern Africa from classical times into the Middle Ages. It served as a model for the currencies of the Muslim caliphates and the European states during the Middle Ages and the Modern Era. Roman currency names survive today in many countries via the Carolingian monetary system, such as the dinar (from the denarius coin), the British pound (a translation of the Roman libra, a unit of weight), the peso (also a translation of libra), and the words for the general concept of money in the Iberian Romance languages (e.g. Spanish dinero and Portuguese dinheiro).

Commentarii (Latin, Greek: hupomnemata) are notes to assist the memory, or memoranda. This original idea of the word gave rise to a variety of meanings: notes and abstracts of speeches for the assistance of orators; family memorials, the origin of many of the legends introduced into early Roman history from a desire to glorify a particular family; and diaries of events occurring in their own circle kept by private individuals. An example of this is the day-book drawn up for Trimalchio in Petronius's Satyricon (Satyricon, 53) by his actuarius, a slave to whom the duty was specially assigned. Other commentarii were memoirs of events in which they had taken part drawn up by public men. Examples of these are the Commentaries of Caesar: Commentarii de Bello Gallico on the Gallic Wars and Commentarii de Bello Civili on the civil wars; another example is that of Cicero on his consulship. Different departments of the imperial administration and certain high functionaries kept records, which were under the charge of an official known as a commentariis (cf. a secretis, ab epistulis). Municipal authorities also kept a register of their official acts.

The Commentarii Principis were the register of the official acts of the emperor. They contained the decisions, favourable or unfavourable, in regard to certain citizens; accusations brought before him or ordered by him; and lists of persons in receipt of special privileges. These must be distinguished from the commentarii diurni, a daily court-journal. At a later period records called ephemerides were kept by order of the emperor; these were much used by the collection of biographies known as Scriptores Historiae Augustae (see Augustan History). The Commentarii Senatus, only once mentioned (Tacitus, Annals, xv. 74) are probably identical with the Acta Senatus.