Question: During what period was Rome was the largest city in the world and Gaius Julius Cornutus Bryonianus lived?

Context paragraphs:
Julia Tertulla: Julia Tertulla was a Roman woman who lived in the 1st century and 2nd century in the Roman Empire.  Tertulla was the daughter of suffect consul Gaius Julius Cornutus Tertullus and the identity of her mother is unknown.  Tertulla was born and raised in Perga, the capital of the Roman province of Pamphylia.  She was the paternal aunt to Gaius Julius Plancius Varus Cornutus.

Roman Empire: The Roman Empire (Latin: "Imperium Rōmānum" ; ] Koine and Medieval Greek: Βασιλεία τῶν Ῥωμαίων, tr.  "Basileia tōn Rhōmaiōn" ) was the post-Roman Republic period of the ancient Roman civilization, characterized by government headed by emperors and large territorial holdings around the Mediterranean Sea in Europe, Africa and Asia.  The city of Rome was the largest city in the world  100 BC  AD 400 , with Constantinople (New Rome) becoming the largest around AD 500, and the Empire's populace grew to an estimated 50 to 90 million inhabitants (roughly 20% of the world's population at the time).  The 500-year-old republic which preceded it was severely destabilized in a series of civil wars and political conflict, during which Julius Caesar was appointed as perpetual dictator and then assassinated in 44 BC.  Civil wars and executions continued, culminating in the victory of Octavian, Caesar's adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt.  Octavian's power was then unassailable and in 27 BC the Roman Senate formally granted him overarching power and the new title "Augustus", effectively marking the end of the Roman Republic.

Julia (gens): The gens Julia or Iulia was one of the most ancient patrician families at Ancient Rome.  Members of the "gens" attained the highest dignities of the state in the earliest times of the Republic.  The first of the family to obtain the consulship was Gaius Julius Iulus in 489 BC.  The gens is perhaps best known, however, for Gaius Julius Caesar, the dictator, and grand uncle of the emperor Augustus, through whom the name was passed to the so-called Julio-Claudian dynasty of the 1st century AD.  The "nomen Julius" became very common in imperial times, as the descendants of persons enrolled as citizens under the early emperors began to make their mark in history.

Gaius Julius Cornutus Bryonianus: Gaius Julius Cornutus Bryonianus was a Roman who lived in the 1st century in the Roman Empire.  Bryonianus originally came from Perga, the capital of the Roman province of Pamphylia.  Bryonianus could have been related to a certain "Bryonianus Lollianus", a local man of Equestrian Rank from Side, Pamphylia.

Gaius Julius Archelaus Antiochus Epiphanes: Gaius Julius Archelaus Antiochus Epiphanes, also known as Julius Archelaus Epiphanes; Epiphanes; Gaius Julius Antiochus Epiphanes or simply known as Gaius (Greek: ο Γάιος Ιούλιος Αρχέλαος Αντίοχος Επιφανής, 38-92 AD) was an influential prince of the Kingdom of Commagene, who lived in the 1st century.

Gaius Julius Cornutus Tertullus the Younger: Gaius Julius Cornutus Tertullus was a prominent Roman citizen, the son of Gaius Julius Cornutus Tertullus though the identity of his mother is unknown.  He was born and raised in Perga, the capital of the Roman province of Pamphylia.  Unfortunately very little is known on him.

Gaius Julius Cornutus Tertullus: Gaius Julius Cornutus Tertullus was a Roman senator who was active during the late 1st and early 2nd centuries.  He is best known as the older friend of Pliny the Younger, with whom Cornutus was suffect consul for the "nundinium" of September-October 100.

Julii Caesares: The Julii Caesares were the most illustrious family of the patrician "gens Julia".  The family first appears in history during the Second Punic War, when Sextus Julius Caesar was praetor in Sicily.  His son, Sextus Julius Caesar, obtained the consulship in 157 BC; but the most famous descendant of this stirps is Gaius Julius Caesar, a general who conquered Gaul and became the undisputed master of Rome following the Civil War.  Having been granted dictatorial power by the Roman Senate and instituting a number of political and social reforms, he was assassinated in 44 BC.  After overcoming several rivals, Caesar's adopted son and heir, Gaius Julius Caesar Octavianus, was proclaimed Augustus by the senate, inaugurating what became the Julio-Claudian line of Roman emperors.

Gaius Plancius Varus: Gaius Plancius Varus was a Roman who lived between the 1st century and 2nd century in the Roman Empire.  Varus was the son of Roman Senator, Proconsul Marcus Plancius Varus and the Herodian Princess Julia.  His sister was Plancia Magna, he was therefore the maternal uncle to Gaius Julius Plancius Varus Cornutus.  Varus was born and raised in Perga, the capital of the Roman province of Pamphylia.

Julia Iotapa (Cilician princess): Julia Iotapa or Julia Iotape, sometimes known as Julia of Cilicia (born around 80) was a Cilician Princess who lived in the 1st century and 2nd century.  Daughter of King Gaius Julius Alexander of Cetis, she married Gaius Julius Quadratus Bassus, Galatian Roman Senator from Anatolia.

Supporting paragraphs: Gaius Julius Cornutus Bryonianus Roman Empire
Answer: the Roman Empire