Legio XIII Gemina
Map of the Roman empire in AD 125, under emperor Hadrian, showing the LEGIO XIII GEMINA, stationed at Apulum (now Alba Iulia, Romania), in the province of Dacia, from AD 106 to c. 271
Active	57 BC to sometime in the 5th century
Country	Roman Republic and Roman Empire
Type	Roman legion (Caesarian)
Role	Infantry assault (some cavalry support)
Size	Varied over unit lifetime. Approx. 3,500 fighting men + support at the time of creation. Expanded and given the cognomen Gemina in 31 BC.
Garrison/HQ	Burnum, Illyricum (1st century BC) Emona, Pannonia (1st century) Augusta Vindelica, Germania Superior Poetovio, Pannonia (1st century) Roman Dacia (106 – c. 270) Dacia Aureliana (since 270) Babylon in Egypt (400s)
Nicknames	Gemina, "The twin" (since 31 BC) Pia Fidelis, "Faithful and loyal"[1]
Motto	Leo Rugit Rursum (The Lion Roars Again)
Mascot	Lion
Engagements	Gallic Wars (58–51 BC) Battle against the Nervians (57 BC) Battle of Gergovia (52 BC) Battle of Alesia (52 BC)–uncertain Battle of Dyrrhachium (48 BC) Battle of Pharsalus (48 BC) Battle of Thapsus (46 BC) Battle of Munda (45 BC) Battle of Actium (31 BC) 1st and 2nd Battle of Bedriacum (69) Dacian Wars (101–102,105–106) Vexillationes of the 13th participated in many other campaigns.
Commanders
Notable commanders	Julius Caesar, Marcus Salvius Otho, Marcus Antonius Primus

Legio XIII Gemina,^[a] in English the 13th Twin Legion was a legion of the Imperial Roman army. It was one of Julius Caesar's key units in Gaul and in the civil war, and was the legion with which he crossed the Rubicon in January, perhaps the 10th, 49 BCE. The legion appears to have still been in existence in the 5th century CE. Its symbol was the lion.

Legio XIII was levied by Julius Caesar in 57 BCE, before marching against the Belgae, in one of his early interventions in intra-Gallic conflicts. During the Gallic Wars (58–51 BCE), Legio XIII was present at the Battle against the Nervians, the Siege of Gergovia, and while not specifically mentioned in the sources, it is reasonable to assume that Legio XIII was also present for the Battle of Alesia.

After the end of the Gallic wars, the Roman Senate refused Caesar his second consulship, ordered him to give up his commands, and demanded he return to Rome to face prosecution. Forced to choose either the end of his political career or civil war, Caesar brought Legio XIII across the Rubicon river and into Italy. The legion remained faithful to Caesar during the resulting civil war between Caesar and the conservative Optimates faction of the senate, whose legions were commanded by Pompey. Legio XIII was active throughout the entire war, fighting at Dyrrhachium (48 BCE) and Pharsalus (48 BCE). After the decisive victory over Pompey at Pharsalus, the legion was to be disbanded, and the legionaries "pensioned off" with the traditional land grants; however, the legion was recalled for the Battle of Thapsus (46 BCE) and the final Battle of Munda (45 BCE). After Munda, Caesar disbanded the legion, retired his veterans, and gave them farmland in their native Italy.

Augustus reconstituted the legion once again in 41 BCE to deal with the rebellion of Sextus Pompeius (son of Pompey) in Sicily.

Legio XIII acquired the cognomen Gemina ("twin", a common appellation for legions constituted from portions of others) after being reinforced with veteran legionaries from other legions following the war against Mark Antony and the Battle of Actium.^[2] Augustus then sent the legion to Burnum (modern Knin), in Illyricum, a Roman province in the Adriatic Sea.

In 16 BCE, the legion was transferred to Emona (now Ljubljana) in Pannonia, where it dealt with local rebellions.

After the disaster of the Battle of the Teutoburg Forest in 9 CE, the legion was sent as reinforcements to Augusta Vindelicorum (Augsburg), and then to Vindonissa, Raetia, to prevent further attacks from the Germanic tribes.

Emperor Claudius sent them back to Pannonia around 45 and the legion built its legionary fortress at Poetovium (modern Ptuj, Slovenia).

In the year of the four emperors (69), XIII Gemina supported first Otho and then Vespasian against Vitellius, fighting in the two Battles of Bedriacum.

Under Trajan the legion took part in both Dacian wars (101–102, 105–106), and it was transferred by Trajan in 106 to the newly conquered province of Dacia (in Apulum, modern Alba Iulia, Romania) to garrison it.

Vexillationes of the XIII Gemina fought under Emperor Gallienus in northern Italy. The emperor issued a legionary antoninianus celebrating the legion, and showing the legion's lion (259–260).^[3] Another vexillatio was present in the army of the emperor of the Gallic Empire Victorinus: this emperor, in fact, issued a gold coin celebrating the legion and its emblem.^[4]

In 271, the legion was relocated when the Dacia province was evacuated, and restationed in Dacia Aureliana.

In the 5th century, according to the Notitia Dignitatum, a legio tertiadecima gemina was in Babylon in Egypt, a strategic fortress on the Nile at the traditional border between Lower Egypt and Middle Egypt, under the command of the Comes limitis Aegypti.^[5]

Name	Rank	Time frame	Province	Soldier located in	Veteran located in	Source
Aurelius Rufinus [6]	beneficiarius	2nd – 3rd century CE	Dacia	Samum
M. Valerius Valentinus [6]	beneficiarius	2nd – 3rd century CE	Dacia	Samum	-	CIL III, 827
Valerius Vibius Valerianus [6]	beneficiarius	2nd – 3rd century CE	Dacia	Samum	-	CIL III, 823
Ulpius Bacchius [7]	centurion	?	?	?	?	?
L. Valerius Rufus [8]	decurio	after 222 CE	?	?	Sarmizegetusa Ulpia Traiana, Dacia	CIL III, 1485
Vedius Aquila	legatus	69				Tacitus, Histories, III.7
Aelius Vitalis [9]	duplarius	3rd century CE	Dacia	Apulum	Antiochia ad Taurum, Syria?
Aurelius Valerianus [9]	duplarius	3rd century CE	Dacia	Apulum	Antiochia ad Taurum, Syria?
Aulus Julius Pompilius Piso[10]	legatus	c. 173				CIL VIII, 2582 = ILS 1111
Marcus Valerius Maximianus[11]	legatus	c. 182				AE 1956, 124
Gaius Caerellius Sabinus[11]	legatus	c. 183 - c. 185				CIL III, 1092
Proculus[11]	legatus	between 185 and 191
Tiberius Manilius Fuscus[11]	legatus	191-c. 193				CIL III, 1172
Aulus Terentius Pudens Uttedianus[12]	legatus	between 198 and 209				CIL III, 993 = ILS 3923
Quintus Marcius Victor Felix Maximillianus[12]	legatus	reign of Septimius Severus				CIL III, 1118
Lucius Annius Italicus Honoratus[12]	legatus	reign of Caracalla				CIL III, 1071, CIL III, 1072
Rufrius Sulpicianus[12]	legatus	reign of Caracalla or Elagabalus				CIL III, 1129 = ILS 3867
Quintus Servaeus Fuscus Cornelianus[12]	legatus	c. 225				CIL VIII, 22721 = ILS 8978 = ILTun 33
Marcus Valerius Longinus[12]	legatus	reign of Alexander Severus				CIL III, 1019, CIL III, 1020
Gaius Rutilius Gallicus	military tribune	c. 52				AE 1920, 55
L. Maecius L.f. Postumus	military tribune	c. 72				AE 1934, 248
C. Caelius C.f. Martialis	military tribune	before 106				AE 1934, 2
Sextus Julius Severus	military tribune	before 110				CIL III, 2830 = ILS 1056
Aulus Junius Pastor	military tribune	c. 149				CIL VI, 1435
Aulus Julius Pompilius Piso	military tribune	c. 165				CIL VIII, 2582 = ILS 1111
Quintus Hedius Lollianus Plautius Avitus[13]	military tribune	c. 192	Dacia			CIL V, 4347 = ILS 1149
Publius Catius Sabinus	military tribune	before 206	Dacia			CIL III, 5727
C. Cassio C. f. Volt[inia] [14]	military tribune	?	?	?	-	?
Caius [7]	speculator	2nd – 3rd century CE	Dacia	Apulum	-	CIL III, 14479; IDR III/5, 426
Cocceius [7]	speculator	2nd – 3rd century CE	Dacia	Apulum	-	CIL III, 14479; IDR III/5, 426
C. Iulius Valerius [8]	?	222 – 235 CE	Dacia ?	?	Sarmizegetusa Ulpia Traiana, Dacia	CIL III, 1933
Lucius Dasumius Priscus[8]	?	2nd century CE	?	?	Sarmizegetusa Ulpia Traiana, Dacia	CIL III, 1476
Lucius Furius	?	1st century CE	Gallia Aquitania	Mediolanum Santonum	Aunedonnacum
Lucius Autius	?	1st century CE	Gallia Aquitania	Mediolanum Santonum	Aunedonnacum
Marcus Aurelius Timoni [15]	?	2nd - 3rd century CE	Dacia ?	Castra of Sânnicolau Mare ?	Castra of Sânnicolau Mare, Dacia	IDR III/1, 274
M[arcus] Ulp[ius]	?	2nd – 3rd century CE	Dacia	?	Apulum	IDR III/5, 180
P. Aelius Valerianus [7]	speculator	2nd - 3rd century CE	Dacia	Apulum	-	IDR III/5, 721
Publius Urvinus	?	?	Raetia	Augusta Vindelicorum ?	-	CIL XIII, 6884
Q. Julius Secundinus [8]	?	2nd century CE	Dacia ?	?	Sarmizegetusa Ulpia Traiana, Dacia	CIL III, 1971
Statius Alexander [7]	speculator	2nd – 3rd century CE	Dacia	Apulum	-	Apulum 40, 2007, 176–177
Ulpius Proculinus [7]	speculator	Gordian's reign	Dacia	Apulum	-	CIL III, 7794b; IDR III/5, 435

• - Marco Cornelio Marci filio Galeria (tribu) Nigrino / Curiatio Materno consuli - / - tribuno militum legionis XIIII Geminae (...). Liria, Spain. CIL II2/14.
• - Caio Iulio Galeria (tribu) Lepido Iessonensi primi pilari centurioni legionis XIII Geminae Piae Fidelis centurioni (...). Lerida (Ilerda), Spain. CIL II 4463.

• A fictionalized account of the actions of Legio XIII Gemina during the struggle between Julius Caesar and the Optimates faction under Pompey can be seen in the joint HBO/BBC/RAI television production Rome, most notably two of its soldiers: Centurion Lucius Vorenus and Legionary Titus Pullo, named after real-life Centurions Lucius Vorenus and Titus Pullo of the Legio XI Claudia. The show includes a fictional incident where the legion's eagle standard is stolen by the Gaulish brigands.

• Roman legion
• List of Roman legions
• Dacia Ripensis

• "Notitia Dignitatum". Retrieved 2006-11-22.

• Lendering, Jona. "Legio XIII Gemina". Retrieved 2006-11-18.
• Cowan, Ross (2003). Imperial Roman Legionary AD 161–284. Angus McBride (illust). Osprey Publishing. ISBN 1-84176-601-1.

Media related to Legio XIII Gemina at Wikimedia Commons

• LEGIO XIII GEMINA, Italian re-enactment group (in Ariminum and Bononia)
• LEG XIII GEM, Austrian re-enactment group
• LEGIO XIII GEMINA Blog (Roman reenactment group inside the virtual world of Second Life)
• Legio XIIII Gemina Martia Victrix (Roman Military Research Society)