Gaius Antius Aulus Julius Quadratus

Gaius Antius Aulus Julius Quadratus (; fl. 1st and 2nd centuries) was a Roman senator from Pergamon, who was appointed consul twice, in AD 94 and then in AD 105, the first senator from the Eastern Mediterranean to achieve the ordinary consulship.

Biography Gaius Antius Aulus Julius Quadratus was of Greek descent. Some hold the view he was born in Pergamon, probably in the early 50s, but Anthony Birley states he was only an incomer and that Aristides refers to this man as coming to Pergamum 'at the summons of the god'. Aulus Julius Quadratus was the son of Aulus, and a wealthy patron of the city; his sister was named Julia Polla. Ronald Syme believed he was related to the general Gaius Julius Quadratus Bassus, although Quadratus was a member of the Roman tribe Voltina and Bassus belonged to the tribe Fabia. Olli Salomies has argued his family came from Gallia Narbonensis, Quadratus was also co-opted into the Arval Brethren at some point before March of 78 when he is first mentioned in their Acta Arvalia. From 79–80, he was proconsular legate to the proconsul of Asia, Marcus Ulpius Traianus, father of the future Emperor Trajan. He would subsequently become a close personal friend of the Emperor Trajan, who honoured him as an amicus clarissimus ('most brilliant friend').

Syme infers that Quadratus served as proconsular legate in Bithynia et Pontus from 80-81. Quadratus was appointed governor of the public province of Crete and Cyrenaica in 84/85. He is mentioned again in the Acta Arvalia from January 86 to May 89, indicating he was residing at Rome during that time. In the gap after May 89, he served the emperor as governor of Lycia et Pamphylia from the year 89 to 93

At some point between 89 and 94, Quadratus added the prefix "Gaius Antius" to his name, likely as a requirement for accepting a legacy from an acquaintance.

As a reward for his long service he was elected ordinary consul in AD 105. He was the first senator of eastern origin to achieve this post. In the same year he was appointed priest of Dionysus Kathegemon in Pergamon. Later the Pergamenes also appointed him gymnasiarch for life, in which role he may have been responsible for the construction of a new aqueduct bringing the water of the Caicus river to the city. He was finally appointed proconsular governor of Asia in AD 109/110. His name appears on four issues of coinage at Pergamon, minted during this year. Following this, he convinced Trajan to grant the city a neocorate status for a second time, probably in AD 114/5. Pergamon was the first city in the Empire to achieve this honour, which entitled the city to erect a second temple dedicated to the Imperial cult, the Trajaneum, dedicated to the emperor Trajan and Zeus. The epithet under which Zeus was worshipped in this temple, Philius ('of friendship') may have been a reference to the friendship between Trajan and Quadratus. Also in 114/5, Quadratus established regular games, the Traianeia Deiphilia in honor of Trajan and Zeus Philius.

It is unclear whether he lived into the reign of Hadrian or saw the completion of the Trajaneum in AD 129.