Client kingdoms in ancient Rome

The Romans realized that the task of ruling and assimilating a large number of peoples at once was almost impossible, and that a plan of gradual annexation would be simpler, leaving the provisional organization in the hands of princes born and raised in the country of origin.

Sometimes such serious unrest occurred in some of the "client kingdoms" that the very borders of adjacent provinces were threatened, so much so that it was necessary to intervene directly with Roman armies: for instance, during the Tacfarinas revolt in Africa, where it was necessary to send a second legion, the IX Hispana.

For these reasons, in order to reduce such risks to an absolute minimum, it was deemed more appropriate in some cases to "encompass" these Kingdoms, building along their borders a linear defense system, manned by numerous Roman military posts and capable of repelling external enemy invasions immediately.

), some Greek colonies in the eastern Adriatic Sea (from Apollonia, to Kerkyra, Epidamnos and Issa), being attacked by the Illyrian pirates of Queen Teuta, also decided to come in fidem of Rome, asking for its direct military intervention.

Queen Teuta was forced to sign the peace and leave present-day Albania, while Rome became to all intents and purposes the patron state of the cities of Apollonia, in Kerkyra, Epidamnos and Issa, as well as Oricus, Dimale and the "client" king Demetrius of Pharos.

It consisted of five cities, all of Greek origin, constituting the so-called Cyrenaic Pentapolis, namely: the capital Cyrene with its port of Apollonia (today Marsa Susa), Teuchira-Arsinoe, Euesperides-Berenice (Benghazi) and Barce-Ptolemais (Al Marj).

To Tigranes II he left Armenia; to Pharnaces the Bosporus; to Ariobarzanes Cappadocia and some neighboring territories; to Antiochus of Commagene he added Seleucia and parts of Mesopotamia that he had conquered; to Deiotarus, tetrarch of Galatia, he added the territories of Armenia Minor bordering Cappadocia; he made Attalus the prince of Paphlagonia and Aristarchus that of Colchis; he appointed Archelaus priest of the goddess worshipped at Comana; and finally he made Castor of Phanagoria a faithful ally and friend of the Roman people.

The Senate decided to intervene and persuaded Ariovistus to suspend his conquests in Gaul; in return it offered him, at the suggestion of Caesar (who was consul in 59 BC), the title of rex atque amicus populi Romani ("king and friend of the Roman people").

[...] The friendly and allied kings founded cities under the name of Caesarea, each in his own kingdom, and all together decided to complete, at their own expense, the temple of Jupiter Olympius in Athens, begun some centuries before, dedicating it to the Genius of Augustus.

He cared for these kingdoms as if they were part of the imperial provincial system, going so far as to assign an adviser to princes who were too young or inexperienced, waiting for them to grow and mature; raising and educating the sons of many kings so that many of them would return to their territories to rule as allies of the Roman people.

[35] It was a region of fundamental importance for the political balance of the entire eastern area: it played a buffer role between the Roman empire in the west and that of the Parthians in the east, and both wanted to make it their own vassal state, which would ensure the protection of their borders from their enemies.

[36][37] The Parthians, frightened by the advance of the Roman legions, compromised and signed a peace with Augustus, who had meanwhile arrived in the east from Samos, returning the insignia and prisoners they had taken possession of after their victory over Marcus Licinius Crassus at the Battle of Carrhae in 53 BCE.

[38] Upon his arrival, therefore, Tiberius had merely proceeded to crown Tigranes, who took the name Tigranes III, as client king in a peaceful and solemn ceremony held before the eyes of the Roman legions, while Augustus was proclaimed imperator for the ninth time,[39] and announced in the senate the vassalage of Armenia without, however, decreeing its annexation,[40] so much so that he wrote in his Res gestae divi Augusti: —Augustus, Res gestae divi Augusti, 27.In the West, at the end of three years of military campaigns in Germania Magna (14 to 16), Germanicus had succeeded in gaining the alliance of numerous Germanic peoples north of the Danube and east of the Rhine, who had now become "clients" (such as the Angrivarii), after the campaign of 16, or the Batavi, Frisii and Chauci along the North Sea coast, at least until the time of Claudius.

[44] The difficult situation in the East necessitated Roman intervention, and in 18 Tiberius sent his adopted son, Germanicus, who was appointed consul and awarded the imperium proconsolaris maius over all the eastern provinces, accompanied by the new governor of Syria, Gnaeus Calpurnius Piso.

[48] The arrangement of the East prepared by Germanicus ensured peace until 34: in that year King Artabanus II of Parthia, convinced that Tiberius, now an old man, would not resist from Capri, placed his son Arshak on the throne of Armenia after Artaxias' death.

[58] Following the first phase of the conquest of Britain, the Iceni people (starting in 47), obtained semi-independence from Rome, knowing the latter that upon the death of their king, Prasutagus, these territories would be incorporated into those of the neighboring Roman province.

After retaking the kingdom in 60 and losing it again in 62, the Romans sent Gnaeus Domitius Corbulo in 63 to the territories of Vologases I of Parthia, who succeeded in restoring Armenia to client status,[60] which remained there until the following century, when Trajan undertook a new series of military campaigns against the Parthians (in 114).

In the years around 72-74 he reorganized the eastern part of the Roman Empire, reducing Achaia, Lycia, Rhodes, Byzantium, and Samos to provinces, taking away their freedom; he did the same with Cilicia Trachea and Commagene (in 72),[62] which until then had been ruled by kings.

The expedition against the Suebian peoples was a strategic mistake, since Domitian had to abandon the Dacian front, in a very favorable situation after his recent victory at Tapae over Decebalus (of 88), and settle for a peace unfavorable to Rome, which forced the Roman Empire to postpone its conquest to a future date.

[69] Masyas, king of the Semnones, and Ganna (who was a virgin priestess who had succeeded Veleda in Germania), presented themselves to Domitian, and after receiving honors from the emperor, they departed.In the course of Trajan's conquest of Dacia in 101-106, the Roman emperor succeeded in obtaining military aid from the ancient Sarmatian ally, the Iazyges (who had just been brought back to obedience after a decade of new wars waged against them and their allies, the Suebi) against the Dacian king, Decebalus, who had disregarded the covenants of amicitia and "clientele" toward Rome made during the time of Domitian (in 89).

[70] As allies of the Romans, the Nabataeans also played the role of bulwark between Rome and the Bedouin peoples, who were disinclined to bow to the empire, nevertheless forwarding their wares to the northern emporiums and often supplying them with goods that came from those areas.

It is known that Trajan, having reached Antioch in January of this year, gathered his legions and his best generals, including Lusius Quietus and Quintus Marcius Turbo[74] (then praefectus classis Misenis), marched on Armenia and conquered its capital Artaxata.

In 116 Trajan, aware of the growing difficulties of the conquest, thought he had to give up the southern territories of Mesopotamia, making them his "client" kingdom, while placing on the throne a king loyal to him: the young Parthamaspates, crowned by the Roman emperor himself at Ctesiphon.

[75] Hadrian, newly installed on the throne, was forced to fight a new Sarmatian war in the years 117-119, first against the Roxolani of Moldova and Wallachia, and then against the Iazyges of the Tisza River valley (which was followed by the Roman abandonment of western Banat).

He flatly refused to return to the king of the Parthians the royal throne that had been taken as part of the spoils by Trajan, gave the government of the Bosphorus back to Rhoemetalces [King of the Cimmerian Bosporus, present-day Crimea, from 131 to 153], resolving the pendencies the latter had with Eupator, sent reinforcements into Pontus to the Olbiopolites [inhabitants of Olbia or Olbiopolis, an ancient Greek colony that stood near the mouths of the Dnieper and Bug rivers on the Black Sea] who were fighting against the Tauroscites, and defeated the latter, even forcing them to give hostages.

"[81] Between 162 and 166, Lucius Verus was thus forced by his brother, Marcus Aurelius, to lead a new campaign in the East against the Parthians, who had attacked the Roman territories of Cappadocia and Syria the previous year and occupied the "client" kingdom of Armenia.

[82] However, the plague that broke out during the last year of the campaign, in 166, forced the Romans to withdraw from the newly conquered territories, bringing the disease within their own borders, and scourging their population for more than two decades.

The peace stipulated with the neighboring Germanic peoples north of the Danube was handled directly by the emperors themselves, Marcus Aurelius and Lucius Verus, who were now wary of the barbarian aggressors and traveled for these reasons as far as distant Carnuntum (in 168).

The Historia Augusta recounts that Marcus Aurelius would have wished to make the territories of the former "client" peoples of the Quadi and Marcomanni the province of Marcomannia and of the Iazyges, that of Sarmatia, and would have succeeded if Avidius Cassius had not rebelled.

Philip the Arab, on the other hand, dismissed many of these mercenaries, preferring to pay 500,000 denarii to the Sasanians rather than continue the campaign against them, and generating widespread discontent among the federates over the suspension of the customary payment of tribute.