Nero Lucius Domitius (Nero Claudius Drusus Germanicus) (Antium, 37AD – Roma, June 9, 68).
Son of Domitius Enobarbus and of Agrippina Minor, who, after having married Claudius, managed to have the young Nero adopted by him, ensuring his succession as emperor (54). Finely educated, in the first years of his reign Nero was closely controlled by his mother, by his tutor Seneca and by the Praefectum Pretorii Afranius Burrus. His despotic and authoritarian character surfaced and his dictatorial tendencies prevailed, supported by the plebe, who adored him because of his liberality.

Nero got rid of his brother Britannicus in 55, of his mother in 59, of his first wife Octavia (later on he married Poppea and Messalina), of Burrus in 62. After Rome’s fire in 64, he rebuilt the city and his own mansion, the Domus Aurea. When he was accused of having caused the fire, he retorted the blame on the Christians and persecuted them. Hated by the Senators, in 65 Nero ferociously repressed a conspiracy to kill him, organized by Lucius Calpurnius Piso and other prominent citizens. Seneca and the poet Lucanus died in the ferocious repression, among many others. A war campaign against the Parthians – led by Gneus Domitius Corbulo – regained Rome’s control over Armenia; his popularity had by now reached a peak. In Corinth, Nero solemnly proclaimed Greece’s  liberty, granting fiscal immunities to many cities and showing his favour for the eastern provinces of the empire. Revolts in Judea, Gallia, Africa and Spain – where Galba was crowned emperor by the Senate and by the Praetorians – caused his downfall. When Nero realized that everything was lost, he ordered a slave to kill him.

Vespasian (Titus Flavius Vespasianus) (Reate, 17 November, 9 – Cutilia, 24 June 79)
Born from a humble Sabine family, he accomplished military missions in Claudius’ time in Gallia and Britannia. During Nero’s rule he was sent to Judea to repress the revolt (67) and started his campaign until the anarchy caused by Nero’s death compelled him to stop the operations. Vespasian was proclaimed emperor by the eastern legions. He was acknowledged as emperor by the Senate in 69. After leaving the campaign in Judea to his son Titus, Vespasian returned to Italy and started a reconstruction of the imperial image and structures. He wanted to appear as the restorer of peace, law and order, recovering the tradition of August. He reinforced the imperial power and ensured its continuity to his sons Titus and Domitian. Vespasian respected the privileges of the Senate, reorganized the army, the defence of the borders, the judicial system, and raised the taxes in order to recover financial stability. He extended the Roman citizenship (and rule of law) to all Italy. He started the building of the Colosseum.

Titus (Titus Flavius Sabinus Vespasianus). (Roma 39 – Aquae Cutiliae, Sabina, 81) – Son of Vespasian and Flavia Domitilla, he brought to a conclusion the war in Judea, by putting siege to Jerusalem and destroying the Temple (70). He was brought to the power by Vespasian, and succeeded him in 79. In year 80 he inaugurated the Colosseum with lavish games that lasted one hundred days, and died the following year after only two years of rule, which was marked by calamities: the eruption of Mt. Vesuvius and a fire and plague in Rome, on which occasions he generously helped the population. He maintained his father’s policy of respect for the Senate, was lavish in organizing spectacles and avoided pronouncing death sentences, so that he was called clemens.

Domitian (Caesar Domitianus Augustus, original name until AD 81, then Titus Flavius Domitianus (b. Oct. 24, AD 51–d. Sept. 18, AD 96, Rome [Italy])
The second son of the future emperor Vespasian and Flavia Domitilla, was princeps juventutis (an imperial prince) and was consul six times in Vespasian’s lifetime; moreover, it was recognized that he would eventually succeed his brother Titus, who had no son and was 11 years older than him.
On Vespasian’s death, in June 79, Domitian expected the same position as Titus had received under Vespasian, in particular, tribunician power and some form of imperium. These were not granted, and Domitian was evidently antagonistic to his brother and is alleged to have hastened his death, which occurred on Sept. 13, 81.
As emperor, Domitian was hated by the aristocracy. From the Trajanic writers Tacitus and Pliny the Younger (Suetonius is less partisan) it is hard to disentangle stock vituperation from genuine belief, but it seems certain that cruelty and ostentation were the chief grounds of his unpopularity, rather than any military or administrative incompetence. Indeed, his strict control over magistrates in Rome and the provinces won Suetonius’ praise.
In his secretariat he used both freedmen and knights, some of whom retained their posts after his death; and his consilium of close advisers, including senators, involved no departure from precedent. His military and foreign policy was not uniformly successful. Both in Britain and in Germany advances were made by the Romans early in the reign, and the construction of the Rhine-Danube limes (“fortified line”) owes more to Domitian than to any other emperor. But consolidation in Scotland was halted by serious wars on the Danube.
He continued his father’s policy of holding frequent consulates. A grave source of offence was his insistence on being addressed as dominus et deus (“master and god”). The execution of his cousin Flavius Sabinus in 84 was an isolated event, but there are hints of more general trouble about 87.
The crisis came with the revolt of Antonius Saturninus, governor of Upper Germany, on Jan. 1, 89. This was suppressed by the Lower German army, but a number of executions followed, and the law of majestas (treason) was later employed freely against senators. The years 93-96 were regarded as a period of terror hitherto unsurpassed. Among Domitian’s opponents was a group of doctrinaire senators, friends of Tacitus and Pliny and headed by the younger Helvidius Priscus, whose father of the same name had been executed by Vespasian. Their Stoic views were probably the cause of Domitian’s expulsions of “philosophers” from Rome on two occasions.
Domitian’s financial difficulties are a vexing question. Cruelty came earlier in his reign than rapacity, but eventually he regularly confiscated the property of his victims. His building program had been heavy: Rome received a new forum (later called Forum Nervae) and many other works. Then there were Domitian’s new house on the Palatine and his vast villa on the Alban Mount. Meanwhile, the increased army pay was a recurrent cost. Probably only his confiscations averted bankruptcy in the last years.
The conspiracy that caused his murder on Sept. 18, 96, was led by the two praetorian prefects, various palace officials, and the emperor’s wife, Domitia Longina (daughter of Gnaeus Domitius Corbulo). Nerva, who took over the government at once, must clearly have been privy. The Senate was overjoyed at Domitian’s death, but the army took it badly; and the next year they insisted on the punishment of those responsible.

Trajan, also called CAESAR NERVA TRAIANUS GERMANICUS (his original name was MARCUS ULPIUS TRAIANUS) was born in 53 in the province of Baetica, now Spain. He was the first Roman emperor to be born outside Italy.
Son of a provincial governor enrolled by Vespasian in the ranks of the senators, presumably the future emperor grew up either in Rome or in various military headquarters with his father. He served 10 years as a legionary staff tribune. In this capacity he was in Syria while his father was governor, probably in 75. He then held the traditional magistracies through the praetorship, which qualified him for command of a legion in Spain in 89.
Ordered to take his troops to the Rhine River to aid in quelling a revolt against the emperor [Index] Domitian by the governor of Upper Germany, Trajan probably arrived after the revolt had already been suppressed by the governor of Lower Germany.
Trajan clearly enjoyed the favour of Domitian, who in 91 allowed him to hold one of the two consulships, which, even under the empire, remained most prestigious offices.
After Domitian’s assassination on Sept. 18, 96, the conspirators had put forward as emperor the elderly and innocuous Nerva. Nevertheless, the imperial guard (the praetorian cohorts) forced the new emperor to execute the assassins who had secured the throne for him. Therefore, in October 97, Nerva adopted as his successor Trajan. Soon thereafter, on January 27 or 28, Nerva died, and Trajan was accepted as emperor by both the armies and the Senate.
Trajan was a much more active ruler than Nerva had been during his short reign. Instead of returning to Rome at once to accept from the Senate the imperial powers, he remained for nearly a year on the Rhine and Danube rivers, either to make preparations for a coming campaign into Dacia (modern Transylvania and Romania) or to ensure that discipline was restored and defenses strengthened.
When he returned to Rome in 99, he behaved with respect and affability toward the Senate. He was generous to the populace of Rome, to whom he distributed considerable cash gifts, and increased the number of poor citizens who received free grain from the state. For Italy and the provinces, he remitted the gold that cities had customarily sent to emperors on their accession. He also lessened taxes and was probably responsible for an innovation for which Nerva is given credit–the institution of public funds (alimenta) for the support of poor children in the Italian cities. Such endowments had previously been established in Italy by private individuals, notably by Trajan’s close friend, the orator and statesman Pliny the Younger, for his native Comum (modern Como) in northern Italy.
Trajan undertook or encouraged extensive public works in the provinces, Italy, and Rome: roads, bridges, aqueducts, the reclamation of wastelands, the construction of harbours and buildings. Impressive examples survive in Spain, in North Africa, in the Balkans, and in Italy. Rome, in particular, was enriched by Trajan’s projects. A new aqueduct brought water from the north. A splendid public bathing complex was erected on the Esquiline Hill, and a magnificent new forum was designed by the architect Apollodorus of Damascus. It comprised a porticoed square in the centre of which stood a colossal equestrian statue of the emperor. On either side, the Capitoline and Quirinal hills were cut back for the construction of two hemicycles in brick, which, each rising to several stories, provided streets of shops and warehouses.
Behind the new forum was a public hall, or basilica, and behind this a court flanked by libraries for Greek and Latin books and backed by a temple. In this court rose the still-standing Trajan’s Column, an innovative work of art that commemorated his Dacian Wars. Its cubical base, decorated with reliefs of heaps of captured arms, later received Trajan’s ashes. The column itself is encircled by a continuous spiral relief, portraying scenes from the two Dacian campaigns. These provide a commentary on the campaigns and also a repertory of Roman and Dacian arms, armour, military buildings, and scenes of fighting. The statue of Trajan on top of the column was removed during the Middle Ages and replaced in 1588 by the present one of St. Peter.
In 101 he resumed the invasion of Dacia that Domitian had been forced to abandon by Decebalus, the country’s redoubtable king. In two campaigns (101-102 and 105-106), Trajan captured the Dacian capital of Sarmizegethusa (modern Varhély), which lay to the north of the Iron Gate in western Romania; Decebalus evaded capture by suicide. Trajan created a new province of Dacia; this provided land for Roman settlers, opened for exploitation rich mines of gold and salt, and established a defensive zone to absorb movements of nomads from the steppes of southern Russia.
Trajan’s second major war was against the Parthians, Rome’s traditional enemy in the east. The chronology of his campaigns is uncertain. In preparation for them, in 105/106, one of his generals annexed the Nabataean kingdom, the part of Arabia extending east and south of Judaea. Next, about 110, the Parthians deposed the pro-Roman king of [Index] Armenia, whereupon, in 113/114, Trajan campaigned to reinstate him. In the following year (115) he annexed upper [Index] Mesopotamia and, in the same or next year, moved down the Tigris River to capture the Parthian capital of [Index] Ctesiphon. He reached the Persian Gulf, where he is said to have wept because he was too old to repeat Alexander the Great’s achievements in India.
Late in 115, Trajan barely escaped death in an earthquake that devastated Antioch (modern Antakya, Turkey). In 116 revolts broke out both in the newly conquered territories and in Jewish communities in several of the eastern provinces. Trajan, discouraged and in ill health, left Antioch for Rome. He died, in his 64th year, at Selinus (modern Selindi) on the southern coast of Asia Minor. His ashes were returned to Rome for a state funeral and burial in the base of his column. Just before his death was made public, it was announced that he had adopted Hadrian, who in 100 had married Trajan’s favourite niece.

Hadrian, or ADRIAN (in full CAESAR TRAIANUS HADRIANUS AUGUSTUS) was (until AD 117) PUBLIUS AELIUS HADRIANUS (b. Jan. 24, AD 76, Italica, Baetica [now in Spain]–d. July 10, 138, Baiae [Baia], near Naples [Italy]).
The family of Hadrian came from southern Spain. They were not, however, of native Spanish origin but rather of settler stock. Hadrian’s forebears left Picenum in Italy for Spain about 250 years before his birth. Hadrian himself may have been born in Rome. There is nothing particularly Spanish about Hadrian. He bears the stamp of education in cosmopolitan Rome.
When Trajan was consul in 91, Hadrian began to follow the traditional career of a Roman senator, advancing through a conventional series of posts. In 101 Hadrian was quaestor and in 102 served as Trajan’s companion in the Emperor’s first war in Dacia on the Danube. In 105 Hadrian became tribune of the plebs and, exceptionally, advanced to the praetorship in 106. No less exceptional than the speed of promotion was Hadrian’s service as praetor while in the field with the emperor during his second war in Dacia. In 107 he was briefly governor of Lower Pannonia. Then, in 108, Hadrian reached the coveted pinnacle of a senator’s career, the consulate.
In 107 Licinius Sura, a powerful figure who protected Hadrian, had held that office for the third time, an honour vouchsafed to very few. It was a cruel blow when Sura died at an unknown date immediately following Hadrian’s consulate. Hadrian’s career apparently stopped for nearly 10 years. One fact illuminates this otherwise obscure period of Hadrian’s life: he was archon at Athens in 112, and a surviving inscription commemorating this office was set up in the Theatre of Dionysus. Hadrian’s tenure is a portent of the philhellenism that characterized his reign, and it suggests that in a time of political inactivity Hadrian devoted himself to the nation and culture of his beloved Greeks. Somehow, however, Hadrian’s star rose again, and he returned to favour before the Emperor died. On August 9, 117 Hadrian learned that Trajan had adopted him, the sign of succession. On the 11th, it was reported that Trajan had died on the way to Rome, whereupon the army proclaimed Hadrian emperor.
When Hadrian reached Rome in the summer of 118, his position was reasonably stable. He courted popular sentiment by public largesse, gladiatorial displays, and a formal cancellation of debts to the state.The new emperor remained at Rome for three years. In 121 he set forth on a tour of the empire, west and east, to inspect troops and examine frontier defenses. This prolonged absence from the capital of the empire had its administrative justifications. There had been disturbances in some provinces, and the Parthians had to be dealt with; there was a general need for imperial supervision. Nevertheless, another motive impelled the Emperor in his journeys, namely, an insatiable curiosity about everything and everybody. The Christian writer Tertullian called him rightly omnium curiositatum explorator, an explorer of everything interesting. That curiosity was bred of a keen intellect and an anguished spirit. These together drove him inexorably, and by a roundabout path, to the Greek East. After he left Spain early in 123, he never saw the western provinces again. Hadrian soon came to look upon his reign as a new Augustan age. In 123 he began to style himself Hadrianus Augustus, deliberately evoking the memory of his great predecessor; he announced a golden age on his coinage. The peace he so much cherished was a latter-day Augustan peace, and he bequeathed to posterity a public statement of his exploits that imitated the one left by Augustus.
Hadrian spent another three years in Rome, but in 128 he set forth again. After a visit to North Africa, he went to Athens, and from there he sailed to Asia Minor; he penetrated far eastward into Syria and Arabia. Crossing over into Egypt, he explored the Nile; then, for the third time, he went to Athens. It is not certain whether Hadrian returned to Rome in 132 or a little later; he was certainly there in May of 134, but by then a revolt in Judaea forced him abroad still another time. He went to Palestine, not as a tourist but as a commander. That journey was Hadrian’s last.
The irrational element in Hadrian was important. He was an adept in astrology, like many intelligent Romans of the time. He was also an aesthete who ascended Mt. Etna, in Sicily, and Jabal Agra’, near Syrian Antioch, simply to watch the sunrise. He had a lively sense of the past, preferring older writers to more recent ones, favouring archaism for its own sake. He revolutionized style in the empire by wearing a beard and setting a precedent for generations of emperors.
In Bithynium-Claudiopolis (modern Bolu) in northwestern Asia Minor, Hadrian encountered a languid youth, born about 110, by the name of Antinoüs. Captivated by him, Hadrian made Antinoüs his companion. When, as they journeyed together along the Nile in 130, the boy fell into the river and drowned, Hadrian was desolate and wept openly. A report circulated and was widely believed that Antinoüs had cast himself deliberately into the river as a part of some sacred sacrifice.
Although Hadrian himself denied this, the sober 3rd-century historian Dio Cassius thought it was the truth. The religious character, if such there was, of the relation between Hadrian and the boy is totally elusive. The emotional involvement is, however, quite clear. Seeing Hadrian’s grief, the Greek world strove to provide suitable consolation for the bereaved and honour for the deceased. Cults of Antinoüs sprang up all over the East and then spread to the West. Statues of the boy became a common sight. In Egypt the city of Antinoöpolis commemorated his death.
When Hadrian left Rome in 134 for his final journey abroad, it was to resolve a problem of serious proportions in] Judaea. Under the leadership of Bar Kokhba (known also as Bar Koziba), the Jews were in open revolt. What had moved them is not altogether clear. Rabbinical literature alludes to a Hadrianic persecution that caused fear and apostasy. The probable explanation of this kind of reference is a universal ban on circumcision that Hadrian issued in, it seems, the early 130s. The uprising came swiftly and understandably. Hadrian’s visit to Athens in 131-132 and his residence at Rome until the summer of 134 suggest a reluctance to deal personally with the disturbance in Judaea. He first placed an able general, Sextus Julius Severus, in charge of the problem. In the year after Hadrian’s arrival in the Near East, the revolt was over.
Hadrian adopted the profligate Lucius Ceionius Commodus, aged about 36. The extravagant life of Ceionius, later renamed Lucius Aelius Caesar, portended a disastrous reign. Fortunately, he died two years later, and Hadrian, close to death himself, had to choose again. This time he picked an 18-year-old boy named Annius Verus, the future emperor Marcus Aurelius.
In 138 Hadrian arranged for the succession to pass to the young Verus. His arrangements were clever. An estimable and mature senator, Antoninus, was adopted by Hadrian and designated to succeed him. The Emperor, however, required that Antoninus adopt both the young Verus and the eight-year-old son of the recently deceased Ceionius. Thus, the family of his first choice was remembered, whereas an early succession for the older boy seemed assured. No one expected that Antoninus would last very long. Hadrian’s scheme of imposing a double adoption upon his immediate successor looks like another imitation of the first emperor, Augustus, who had made a similar demand of Tiberius. By an irony of fate, Hadrian’s expectations about the future were confounded. Antoninus, like Tiberius, lived far longer than anyone would have thought possible. He did not die until 161.
When Hadrian died at the seaside resort of Baiae, death came to him slowly and painfully. He wrote a letter in which he said how terrible it was to long for death and yet be unable to find it.

(Source: Encyclopedia Britannica)