Question: Who is the mother of the leader that helped the empire where the principate was formed reach its greatest extent?

<P0-S0> The imperial period of Rome lasted approximately 1,500 years compared to the 500 years of the Republican era. <P0-S1> 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 ''. <P0-S2> Following Octavian's victory, the size of the empire was dramatically increased. <P0-S3> After the assassination of Caligula in AD 41, the Senate briefly considered restoring the republic, but the Praetorian Guard proclaimed Claudius emperor instead. <P0-S4> Under Claudius, the empire invaded Britannia, its first major expansion since Augustus. <P0-S5> 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. <P0-S6> The empire reached its greatest extent under Trajan, the second in this line. <P0-S7> 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. <P0-S8> His short reign was followed by the long reign of his brother Domitian, who was eventually assassinated. <P0-S9> The Senate then appointed the first of the Five Good Emperors. <SEP> <P1-S0> the samanid empire (, "sāmāniyān"), also known as the samanian empire, samanid dynasty, samanid emirate, or simply samanids, was a sunni iranian empire from 819 to 999. the empire was centered in khorasan and transoxiana during its existence; at its greatest extent, the empire encompassed all of today's afghanistan, large parts of iran, tajikistan, turkmenistan, uzbekistan, kyrgyzstan, and parts of kazakhstan and pakistan. <SEP> <P2-S0> "standing in the shadows of love" is a 1966 hit single recorded by the four tops for the motown label. <P2-S1> written and produced by motown's main production team holland–dozier–holland, the song is one of the most well-known motown tunes of the 1960s. <P2-S2> a direct follow-up to the #1 hit "reach out i'll be there" (even featuring a similar musical arrangement), "standing in the shadows of love" reached #2 on the soul chart and #6 on the "billboard" hot 100 in 1967. it also reached #6 in the uk. <P2-S3> though the song was well-received, it has received some criticism. <P2-S4> author martin charles strong notes that it rehashed the formula of "reach out i'll be there" and achieved similar success by reaching the top 10 in both the us and uk. <P2-S5> it is ranked #470 on "rolling stone" 's list of the 500 greatest songs of all time. <SEP> <P3-S0> 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). <P3-S1> 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. <P3-S2> 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. <P3-S3> 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. <SEP> <P4-S0> When Diocletian became Roman Emperor in 284 CE, he inherited a constitution that was no longer functioning, and so he enacted the most significant constitutional reforms in over three-hundred years. <P4-S1> His reforms, much like those three-hundred years before, were intended to correct the errors in the previous constitution. <P4-S2> The History of the Constitution of the Late Roman Empire is a study of the ancient Roman Empire that traces the progression of Roman political development from the abolition of the Roman Principate around the year 200 until the fall of the Western Roman Empire in 476 CE. <P4-S3> Diocletian's specific reforms were less radical than was the reality that he exposed the state of government for what it had been for centuries: monarchy. <P4-S4> With Diocletian’s reforms the Principate was abolished, and a new system, the Dominate (Latin: "lord" or "master"), was established.