Editing Hadrian (section)

== Military activities ==
[[File:Statua di Adriano, Antalya, Turchia.jpg|thumb|upright=1.2|Statue of Hadrian in military garb, wearing the [[civic crown]] and [[muscle cuirass]], from [[Antalya]], Turkey.]]

Most of Hadrian's military activities were consistent with his ideology of empire as a community of mutual interest and support. He focused on protection from external and internal threats; on "raising" existing provinces rather than the aggressive acquisition of wealth and territory through subjugation of "foreign" peoples that had characterised the early empire.<ref>Clifford Ando, ''Imperial Ideology and Provincial Loyalty in the Roman Empire''. Berkeley: University of California Press, 2000, {{ISBN|0-520-22067-6}}, p. 330</ref> Hadrian's policy shift was part of a trend towards the slowing down of the empire's expansion, such expansion being not closed after him (the empire's greatest extent being achieved only during the [[Severan dynasty]]), but a significant step in that direction, given the empire's overstretching.<ref>Patrick Le Roux, ''Le Haut Empire Romain en Occident, d'Auguste aux Sévères''. Paris: Seuil, 1998, {{ISBN|2-02-025932-X}}, p. 56</ref> While the empire as a whole benefited from this, military careerists resented the loss of opportunities.

The 4th-century historian Aurelius Victor saw Hadrian's withdrawal from Trajan's territorial gains in [[Mesopotamia]] as a jealous belittlement of Trajan's achievements (''Traiani gloriae invidens'').<ref>W. Den Boer, ''Some Minor Roman Historians'', Leiden: Brill, 1972, {{ISBN|90-04-03545-1}}, p. 41</ref> More likely, an expansionist policy was no longer sustainable; the empire had lost two legions, the [[Legio XXII Deiotariana]] and the "lost legion" [[IX Hispania]], possibly destroyed in a late Trajanic uprising by the [[Brigantes]] in Britain.<ref>[[Yann Le Bohec]], ''The Imperial Roman Army''. London: Routledge, 2013, {{ISBN|0-415-22295-8}}, p. 55</ref> Trajan himself may have thought his gains in Mesopotamia indefensible and abandoned them shortly before his death.<ref>Albino Garzetti, ''From Tiberius to the Antonines (Routledge Revivals): A History of the Roman Empire AD 14–192''. London: Routledge, 2014, {{ISBN|978-1-138-01920-1}}, p. 381</ref> Hadrian granted parts of Dacia to the [[Roxolani]] Sarmatians; their king, Rasparaganus, received Roman citizenship, client king status, and possibly an increased subsidy.<ref>The partial withdrawal was probably supervised by the governor of Moesia [[Quintus Pompeius Falco]]; see Birley, ''Restless Emperor'', pp. 84, 86.</ref> Hadrian's presence on the Dacian front is mere conjecture, but Dacia was included in his coin series with allegories of the provinces.<ref>[[Eutropius (historian)|Eutropius]]'s notion that Hadrian contemplated withdrawing from Dacia altogether appears to be unfounded; see Jocelyn M. C. Toynbee, ''The Hadrianic School: A Chapter in the History of Greek Art''. CUP Archive, 1934, 79</ref> A controlled partial withdrawal of troops from the Dacian plains would have been less costly than maintaining several Roman cavalry units and a supporting network of fortifications.<ref>Julian Bennett, ''Trajan-Optimus Priceps''. Bloomington: Indiana University Press, 2001, {{ISBN|0-253-21435-1}}, p. 165</ref>

Hadrian retained control over [[Osroene]] through the client king [[Parthamaspates of Parthia|Parthamaspates]], who had once served as Trajan's client king of Parthia;<ref>Opper, ''Empire and Conflict'', p. 67</ref> and around 123, Hadrian negotiated a peace treaty with the now-independent Parthia (according to the ''Historia Augusta'', disputed).<ref>{{Cite journal |last=Doležal |first=Stanislav |date=2017 |title=Did Hadrian Ever Meet a Parthian King? |url=https://www.academia.edu/33969517 |journal=AUC Philologica |volume=2017 |issue=2 |pages=111–125 |doi=10.14712/24646830.2017.16 |issn=2464-6830|doi-access=free }}</ref> Late in his reign (135), the [[Alans|Alani]] attacked Roman [[Cappadocia (Roman province)|Cappadocia]] with the covert support of [[Pharasmanes II of Iberia|Pharasmanes]], the king of Caucasian [[Kingdom of Iberia|Iberia]]. The attack was repulsed by Hadrian's governor, the historian [[Arrian]],<ref>N. J. E. Austin & N. B. Rankov, ''Exploratio: Military & Political Intelligence in the Roman World from the Second Punic War to the Battle of Adrianople''. London: Routledge, 2002, p. 4</ref> who subsequently installed a Roman "adviser" in Iberia.<ref>Austin & Rankov, p. 30</ref> Arrian kept Hadrian well-informed on matters related to the Black Sea and the Caucasus. Between 131 and 132, he sent Hadrian a lengthy letter (''Periplus of the Euxine'') on a maritime trip around the Black Sea that was intended to offer relevant information in case a Roman intervention was needed.<ref>Fergus Millar, ''Rome, the Greek World, and the East: Volume 2: Government, Society, and Culture in the Roman Empire''. The University of North Carolina Press, 2005, {{ISBN|0-8078-2852-1}}, p. 183</ref>
[[File:Sardonyx cameo depicting Hadrian being crowned by Oikoumene (personification of the inhabited world) in a chariot pulled by eagles, originally made for Claudius around 50 AD and the head later reworked into a portrait of Hadrian, Altes.jpg|thumb|Sardonyx cameo depicting Hadrian being crowned by Roma in a chariot pulled by eagles as ''ruler of the world''. Possibly made for [[Claudius]] around 50 CE with the head being reworked into a portrait of Hadrian, [[Altes Museum]].]]
Hadrian also developed permanent fortifications and military posts along the empire's borders (''limites'', [[Grammatical number|sl.]] ''limes'') to support his policy of stability, peace and preparedness. That helped keep the military usefully occupied in times of peace; his wall across Britannia was built by ordinary troops. A series of mostly wooden [[fortifications]], forts, [[outpost (military)|outposts]] and [[watchtower (fortification)|watchtowers]] strengthened the Danube and [[Rhine]] borders. Troops practised intensive, regular [[Exhibition drill|drill]] routines. Although his coins showed military images almost as often as peaceful ones, Hadrian's policy was [[peace through strength]], even threat,<ref>Elizabeth Speller, p. 69</ref> with an emphasis on ''disciplina'' (discipline), which was the subject of two monetary series. Cassius Dio praised Hadrian's emphasis on "spit and polish" as cause for the generally peaceful character of his reign.<ref>Opper, p. 85</ref> Fronto, by contrast, claimed that Hadrian preferred war games to actual war and enjoyed "giving eloquent speeches to the armies"&nbsp;– like the inscribed series of addresses he made while on an inspection tour, during 128, at the new headquarters of [[Legio III Augusta]] in [[Lambaesis]].<ref>Birley, ''Restless Emperor'', pp. 209–212</ref>

Faced with a shortage of legionary recruits from Italy and other Romanised provinces, Hadrian systematised the use of less costly [[Numerus (Roman military unit)|''numeri'']]&nbsp;– ethnic non-citizen troops with special weapons, such as Eastern mounted archers, in low-intensity, mobile defensive tasks such as dealing with border infiltrators and skirmishers.<ref>Luttvak, Edward N. ''The Grand Strategy of the Roman Empire: From the First Century A.D. to the Third'', Baltimore: Johns Hopkins University Press, 1979, {{ISBN|0-8018-2158-4}}, p. 123</ref><ref>Christol & Nony, p. 180</ref> Hadrian is also credited with introducing units of heavy cavalry ([[cataphracts]]) into the Roman army.<ref>{{Cite book|url=https://books.google.com/books?id=yglkwD7pKV8C&q=emperor+Hadrian++cataphracts&pg=PA263|title=The History of Central Asia: The Age of the Steppe Warriors– Google Knihy |date= 11 December 2012|access-date=3 September 2016|isbn=978-1-78076-060-5|last1=Baumer |first1=Christoph |publisher=Bloomsbury Academic }}</ref> Fronto later blamed Hadrian for declining standards in the Roman army of his own time.<ref>''Fronto: Selected Letters''. Edited by Caillan Davenport & Jenifer Manley, London: AC & Black, 2014, {{ISBN|978-1-78093-442-6}}, pp. 184f</ref>