Marcus Antonius (Latin: ; January 14, 83 BC – August 1, 30 BC), commonly known in English as Mark or Marc Antony, was a Roman politician and general who played a critical role in the transformation of the Roman Republic from an oligarchy into the autocratic Roman Empire.
Legio X "Equestris" (Latin: Tenth mounted legion), a Roman legion, was levied by Julius Caesar in 61 BC when he was the Governor of Hispania Ulterior.
 The Tenth was the first legion levied personally by Caesar and was consistently his most trusted.
 The name "Equestris" was applied after Caesar mounted legionaries from the Tenth on horses as a ruse in a parley with the German King Ariovistus in 58 BC because he did not trust his Gallic cavalry auxiliaries from the Aedui tribe.
 Legio X was famous in its day and throughout history, because of its portrayal in Caesar's Commentaries and the prominent role the Tenth played in his Gallic campaigns.
 Its soldiers were discharged in 45 BC.
 Its remnants were reconstituted, fought for Mark Antony and Octavian, disbanded, and later merged into X "Gemina".
Lucius Julius Caesar (fl.
 1st century BC) was a Roman politician and senator who was elected consul of the Roman Republic in 64 BC.
 A supporter of his cousin, the Roman dictator Gaius Julius Caesar, Lucius was a key member of the senatorial faction which strove to avoid civil war between the Roman Senate and Marcus Antonius (Mark Antony) in the aftermath of the Dictator's assassination.
Gaius Julius Caesar (Latin: CAIVS IVLIVS CAESAR, ] , born: 13 July 100 BC – 15 March 44 BC), usually called Julius Caesar, was a Roman politician and general who played a critical role in the events that led to the demise of the Roman Republic and the rise of the Roman Empire.
 He is also known as a notable author of Latin prose.
Hispania ( ; ] ) was the Roman name for the Iberian Peninsula.
 Under the Republic, Hispania was divided into two provinces: Hispania Citerior and Hispania Ulterior.
 During the Principate, Hispania Ulterior was divided into two new provinces, Baetica and Lusitania, while Hispania Citerior was renamed Hispania Tarraconensis.
 Subsequently, the western part of Tarraconensis was split off, first as Hispania Nova, later renamed Callaecia (or Gallaecia, whence modern Galicia).
 From Diocletian's Tetrarchy (AD 284) onwards, the south of remaining Tarraconensis was again split off as Carthaginensis, and probably then too the Balearic Islands and all the resulting provinces formed one civil diocese under the "vicarius" for the Hispaniae (that is, the Celtic provinces).
 The name, Hispania, was also used in the period of Visigothic rule.
Legio quarta decima Gemina ("The Twinned Fourteenth Legion") was a legion of the Imperial Roman army, levied by Julius Caesar in 57 BC.
 The cognomen "Gemina" (Twinned) was added when the legion was combined with another understrength legion after the Battle of Actium.
 The cognomen "Martia Victrix" (martial & victorious) was added sequentially following their service in the Pannonian War c. AD 9 and the defeat of Boudicca in AD 61.
 The emblem of the legion was the Capricorn, as with many of the legions levied by Caesar, their shield device displayed the thunderbolt of Jupiter with wings.
 It was the only legion to do so in the same manner as the Praetorian Guard.
Hispania Citerior (English: "Hither Spain", or "Nearer Spain") was a Roman Province in Hispania during the Roman Republic.
 It was on the eastern coast of Spain down to the town of Cartago Nova, today's Cartagena in the autonomous community of Murcia, Spain.
 It roughly covered today's Spanish autonomous communities of Catalonia and Valencia.
 Further south there was the Roman Province of Hispania Ulterior ("Further Spain"), being further away from Rome.
 The two provinces were formed in 197 BC, four years after the end of the Second Punic War (218-201 BC).
 During this war Scipio Africanus defeated the Carthaginians at the Battle of Ilipa (near Seville) in 206 BC.
 This led to the Romans taking over the Carthaginian possessions in southern Spain and on the east coast up to the River Ebro.
 Several governors of Hispania Citerior commanded wars against the Celtiberians who lived to the west of this province.
 In the late first century BC Augustus reorganised the Roman provinces in Hispania and Hispania Citerior was replaced by the larger province of Hispania Tarraconensis, which included the territories the Romans had conquered in central, northern and north-western Hispania.
 Augustus also renamed Hispania Ulterior Hispania Baetica and created a third province, Hispania Lusitania.
Gaius Crastinus (c. 85 BC – 48 BC) was a soldier in Julius Caesar's 10th legion during his Gallic Wars.
 He had first joined either the 8th or 9th legion in 65 BC, when Pompey Magnus had first raised these two legions in Spain.
 He transferred over to the 10th legion as a junior-grade centurion in 61 BC when it was first formed, after being handpicked by Caesar.
 After joining the 10th legion, he commanded a Century.
 Crastinus fought throughout Caesar's Gallic campaigns, and was present at the Battle of Alesia, where he witnessed the surrender of the Gallic chieftain Vercingetorix to the forces of the Roman Republic.
 Early in the war, Crastinus commanded his unit as it repelled an attempted crossing of a river by the Helvetii.
 Crastinus, whom Caesar considered to be amongst his best soldiers, was promoted by Caesar to the rank of Primus Pilus, or "First File" Centurion.
 This rank was one of exceptional prestige, since centurions of this rank commanded the first ("primus"), and most important, century in a Legion.
 With this rank, Crastinus also would have outranked all other centurions in his legion, as it was the highest possible rank of any enlisted Roman soldier.
Legio decima Gemina ("The Twins' Tenth Legion"), was a legion of the Imperial Roman army.
 It was one of the four legions used by Julius Caesar in 58 BC, for his invasion of Gaul.
 There are still records of the X "Gemina" in Vienna in the beginning of the 5th century.
 The legion symbol was a bull.
 Early on in its history, the legion was called X "Equestris" ("mounted"), because Caesar once used the legionaries as cavalry.
Legio quinta alaudae ("Lark-crested Fifth Legion"), sometimes also known as Gallica, was a legion of the Imperial Roman army founded in 52 BC by the general Gaius Julius Caesar (dictator of Rome 49-44 BC).
 It was levied in transalpine Gaul to fight the armies of Vercingetorix, and was the first Roman legion to comprise non-citizens.
 The legion was destroyed in AD 86 at the battle of Tapae in Domitian's Dacian War.

Question: Legio X "Equestris" (Latin: Tenth mounted legion), a Roman legion, was levied by Julius Caesar in 61 BC when he was the Governor of Hispania Ulterior, after its soldiers were discharged,its remnants were reconstituted, fought for Mark Antony, Marcus Antonius, was a Roman politician and general who played a critical role in the transformation of the Roman Republic, from an oligarchy which autocratic time period?
Answer: Roman Empire