Question: Who is the mother of the empire of Galen's country of citizenship during its greatest extent?

full_context: Document 1: Salonia Matidia: Salonia Matidia (4 July 68 CE – 23 December 119 CE) was the daughter and only child of Ulpia Marciana and wealthy praetor Gaius Salonius Matidius Patruinus. Her maternal uncle was the Roman emperor Trajan. Trajan had no children and treated her like his daughter. Her father died in 78 CE and Matidia went with her mother to live with Trajan and his wife, Pompeia Plotina.
Document 2: Trajan: As a civilian administrator, Trajan is best known for his extensive public building program, which reshaped the city of Rome and left numerous enduring landmarks such as Trajan's Forum, Trajan's Market and Trajan's Column. Early in his reign, he annexed the Nabataean Kingdom, creating the province of Arabia Petraea. His conquest of Dacia enriched the empire greatly, as the new province possessed many valuable gold mines.
Document 3: Black Death: The Black Death was one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia and peaking in Europe from 1346 to 1353. The bacterium Yersinia pestis, resulting in several forms of plague, is believed to have been the cause. The plague created a series of religious, social, and economic upheavals, which had profound effects on the course of European history.
Document 4: Trajan: Marcus Ulpius Traianus was born on 18 September 53AD in the Roman province of Hispania Baetica (in what is now Andalusia in modern Spain), in the city of Italica (now in the municipal area of Santiponce, in the outskirts of Seville). Although frequently designated the first provincial emperor, and dismissed by later writers such as Cassius Dio (himself of provincial origin) as "an Iberian, and neither an Italian nor even an Italiot", Trajan appears to have hailed on his father's side from the area of Tuder (modern Todi) in Umbria, at the border with Etruria, and on his mother's side from the Gens Marcia, of an Italic family of Sabine origin. Trajan's birthplace of Italica was founded as a Roman military colony of "Italian" settlers in 206BC, though it is unknown when the Ulpii arrived there. It is possible, but cannot be substantiated, that Trajan's ancestors married local women and lost their citizenship at some point, but they certainly recovered their status when the city became a municipium with Latin citizenship in the mid-1st century BC.
Document 5: Black Death: The Black Death, also known as the Great Plague, the Black Plague, or the Plague, was one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia and peaking in Europe from 1347 to 1351. The bacterium Yersinia pestis, which results in several forms of plague, is believed to have been the cause. The plague created a series of religious, social and economic upheavals, which had profound effects on the course of European history.
Document 6: Plague doctor: The first European epidemic of the bubonic plague dates back to the mid 6th century and is called the Plague of Justinian. The largest plague epidemic was the Black Death in Europe in the 14th century. In medieval times, the large loss of people (due to the bubonic plague) in a town created an economic disaster. Community plague doctors were quite valuable and were given special privileges; for example, plague doctors were freely allowed to perform autopsies, which were otherwise generally forbidden in Medieval Europe, to research a cure for the plague.In some cases, plague doctors were so valuable that when Barcelona dispatched two to Tortosa in 1650, outlaws captured them en route and demanded a ransom. The city of Barcelona paid for their release. The city of Orvieto hired Matteo fu Angelo in 1348 for four times the normal rate of a doctor of 50-florin per year. Pope Clement VI hired several extra plague doctors during the Black Death plague. They were to attend to the sick people of Avignon. Of 18 doctors in Venice, only one was left by 1348: five had died of the plague, and 12 were missing and may have fled.
Document 7: Roman Republic: The Roman Republic (Latin: Res publica Romana; Classical Latin: [ˈreːs ˈpuːb.lɪ.ka roːˈmaː.na]) was the period of ancient Roman civilization beginning with the overthrow of the Roman Kingdom, traditionally dated to 509 BC, and ending in 27 BC with the establishment of the Roman Empire. It was during this period that Rome's control expanded from the city's immediate surroundings to hegemony over the entire Mediterranean world. During the first two centuries of its existence, the Roman Republic expanded through a combination of conquest and alliance, from central Italy to the entire Italian peninsula. By the following century, it included North Africa, Spain, and what is now southern France. Two centuries after that, towards the end of the 1st century BC, it included the rest of modern France, Greece, and much of the eastern Mediterranean. By this time, internal tensions led to a series of civil wars, culminating with the assassination of Julius Caesar, which led to the transition from republic to empire. The exact date of transition can be a matter of interpretation. Historians have variously proposed Julius Caesar's crossing of the Rubicon River in 49 BC, Caesar's appointment as dictator for life in 44 BC, and the defeat of Mark Antony and Cleopatra at the Battle of Actium in 31 BC. However, most use the same date as did the ancient Romans themselves, the Roman Senate's grant of extraordinary powers to Octavian and his adopting the title Augustus in 27 BC, as the defining event ending the Republic.
Document 8: Roman Empire: The Roman Empire (Latin: Imperium Rōmānum, Classical Latin: (ɪmˈpɛ. ri. ũː roːˈmaː. nũː); Koine and Medieval Greek: Βασιλεία τῶν Ῥωμαίων, tr. Basileia tōn Rhōmaiōn) was the post-Roman Republic period of the ancient Roman civilization, with a 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 c. 100 BC -- c. AD 400, with Constantinople (New Rome) becoming the largest around AD 500, and the Empire's population 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 had been 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.
Document 9: Black Death: The Black Death, also known as the Great Plague, the Black Plague, or simply the Plague, was one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia and peaking in Europe from 1347 to 1351. The bacterium Yersinia pestis, which results in several forms of plague, is believed to have been the cause. The plague created a series of religious, social and economic upheavals, which had profound effects on the course of European history.
Document 10: Roman conquest of the Iberian Peninsula: The Roman conquest of Hispania was a process by which the Roman Republic seized the Carthaginian territories in the south and east in 206 BC (during the Second Punic War) and then gradually extended control over most of the Iberian Peninsula without annexations. It was completed after the fall of the Republic (27 BC), by Augustus, the first Roman emperor, who annexed the whole of Hispania to the Roman Empire in 19 BC. Hispania was the Roman name for the Iberian Peninsula. The peninsula had various ethnic groups and a large number of tribes.
Document 11: Antonine Plague: The Antonine Plague of 165 to 180 AD, also known as the Plague of Galen (from the name of the Greek physician living in the Roman Empire who described it), was an ancient pandemic brought back to the Roman Empire by troops returning from campaigns in the Near East. Scholars have suspected it to have been either smallpox or measles, but the true cause remains undetermined. The epidemic may have claimed the life of a Roman emperor, Lucius Verus, who died in 169 and was the co-regent of Marcus Aurelius Antoninus, whose family name, Antoninus, has become associated with the epidemic. The disease broke out again nine years later, according to the Roman historian Dio Cassius (155–235), causing up to 2,000 deaths a day in Rome, one quarter of those who were affected, giving the disease a mortality rate of about 25%. The total deaths have been estimated at five million, and the disease killed as much as one-third of the population in some areas and devastated the Roman army.
Document 12: Roman Empire: The imperial period of Rome lasted approximately 1,500 years compared to the 500 years of the Republican era. The first two centuries of the empire's existence were a period of unprecedented political stability and prosperity known as the Pax Romana, or ``Roman Peace ''. Following Octavian's victory, the size of the empire was dramatically increased. After the assassination of Caligula in AD 41, the Senate briefly considered restoring the republic, but the Praetorian Guard proclaimed Claudius emperor instead. Under Claudius, the empire invaded Britannia, its first major expansion since Augustus. After Claudius' successor, Nero, committed suicide in AD 68, the empire suffered a series of brief civil wars, as well as a concurrent major rebellion in Judea, during which four different legionary generals were proclaimed emperor. Vespasian emerged triumphant in AD 69, establishing the Flavian dynasty, before being succeeded by his son Titus, who opened the Colosseum shortly after the eruption of Mount Vesuvius. His short reign was followed by the long reign of his brother Domitian, who was eventually assassinated. The Senate then appointed the first of the Five Good Emperors. The empire reached its greatest extent under Trajan, the second in this line.
Document 13: Roman Republic: The extensive campaigning abroad by Roman generals, and the rewarding of soldiers with plunder on these campaigns, led to a general trend of soldiers becoming increasingly loyal to their generals rather than to the state. Rome was also plagued by several slave uprisings during this period, in part because vast tracts of land had been given over to slave farming in which the slaves greatly outnumbered their Roman masters. In the 1st century BC at least twelve civil wars and rebellions occurred. This pattern continued until 27 BC, when Octavian (later Augustus) successfully challenged the Senate's authority, and was made princeps (first citizen).
Document 14: Roman mythology: The Aeneid and Livy's early history are the best extant sources for Rome's founding myths. Material from Greek heroic legend was grafted onto this native stock at an early date. The Trojan prince Aeneas was cast as husband of Lavinia, daughter of King Latinus, patronymical ancestor of the Latini, and therefore through a convoluted revisionist genealogy as forebear of Romulus and Remus. By extension, the Trojans were adopted as the mythical ancestors of the Roman people.
Document 15: 1st century: During this period, Europe, North Africa and the Near East fell under increasing domination by the Roman Empire, which continued expanding, most notably conquering Britain under the emperor Claudius (AD 43). The reforms introduced by Augustus during his long reign stabilized the empire after the turmoil of the previous century's civil wars. Later in the century the Julio - Claudian dynasty, which had been founded by Augustus, came to an end with the suicide of Nero in AD 68. There followed the famous Year of Four Emperors, a brief period of civil war and instability, which was finally brought to an end by Vespasian, ninth Roman emperor, and founder of the Flavian dynasty. The Roman Empire generally experienced a period of prosperity and dominance in this period and the First Century is remembered as part of the Empire's golden age.
ground_truth: Marcia
sub_queries: Galen >> country of citizenship Answer: Roman Empire
when did Roman Empire reach its greatest extent Answer: under Trajan
Who is under Trajan 's mother? Answer: Marcia