Legio XIII Gemina

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 (Ceasarian)
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)
Nickname(s)	Gemina, "The twin" (since 31 BC) Pia Fidelis, "Faithful and loyal"
Mascot(s)	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 tertia decima Geminia, in English the 13th Twin Legion, also known as Legio tertia decima Gemina, 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 famously crossed the Rubicon on January 10, 49 BC. The legion appears to have still been in existence in the 5th century AD. Its symbol was the lion.

Legio XIII was levied by Julius Caesar in 57 BC, before marching against the Belgae, in one of his early interventions in intra-Gallic conflicts. During the Gallic Wars (58–51 BC), 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 BC) and Pharsalus (48 BC). 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 BC) and the final Battle of Munda (45 BC). After Munda, Caesar disbanded the legion, retired his veterans, and gave them farmland in Italy.