Legio secunda Traiana Fortis, (Second Valliant Trajanic Legion), was a Roman legion levied by emperor Trajan in 105, along with XXX Ulpia Victrix, for the campaigns in Dacia. There are still records of the II Traiana Fortis in Egypt in the middle of the 5th century. The legion's emblem was the demi-god Hercules.
In 115, II Traiana Fortis was incorporated in the large army used for Trajan's Parthian Campaign. In 117, the legion was allocated in Iudaea, to insure peace after the rebellion that was just ending. In 125 they were sent to Aegyptus for the first time, to share camp in Nicopolis (next Alexandria, Aegyptus) with XXII Deiotariana. Between 132-136 they were again in Iudaea to deal with another revolt.
The legion was in its base in Nicopolis when a revolt against roman rule started in south Egypt. The rebels besieged Alexandria for months. Plague and famine recked the city. But the defenders remained calm. Rescue for the Traiana and the Deiotariana|XXII "Deiotariana" was when Avidius Cassius came with the legions of Syria. The legion was awarded the "Fortis" title for the valiant defense of "Rome's Bread Basket" Fortis meaning Valiant. Cassius was ruler of the east for a time, while Marcus Aurelius was busy in his Marcomanii Wars. When Cassius got the blessing of Aurelius' wife, Cassius declared himself emperor, thinking his emperor dead, but he was still breathing, the legion learned the legions of the Danube were being led by none other than Aurelius himself to fight the rebels. The legion, with the others, cut off Cassius' head, and sent it to Aurelius, who interestingly, let the legions be, just sending them back to their proper posts to watch the Parthian Empire.
The history of II Traiana Fortis gives an example of the political role of the legions. In 194, Pescennius Niger, governor of the province of Syria, rebelled with the support of, among others, II Traiana Fortis. His rival was Septimius Severus who would become emperor. In the days before the final battle, the legion changed sides and vowed fidelity to Severus. This would prove to be decisive for Pescennius' defeat.
In the beginnings of the 3rd century, the legion is involved in Caracalla's campaign against Germanic tribes and receives the cognomen Germanica.
According to Notitia Dignitatum (a c. 400 document), in early 5th century II Traiana Fortis was moved to Apollonopolis Magna, in southern part of Aegyptus, and later it served, at least with some vexillationes, under the Comes limitis Aegypti.