Legio II Adiutrix, the helper, was a Roman legion levied by emperor Vespasian on 70 AD, from Roman navy marines. There are still records of the II Adiutrix in the Rhine border in the beginning of the 4th century AD. The legion's symbols were a Capricorn and Pegasus.
The first assignment of II Adiutrix was in Germania Inferior, where the Batavian rebellion was at its peak. After the defeat of the rebels, the II Adiutrix followed general Cerealis to Britain to deal with another rebellion led by Venutius. During the next years, the legion was to stay in the British Islands to subdue the rebel tribes of Scotland and Wales, with base camp probably at Chester.
In 87, the legion was recalled to the continent to participate in the Dacian wars of emperor Domitian. Between 94 and 95 AD, still in Dacia, future emperor Hadrian served as military tribune in the II Adiutrix.
- Lucius Verus campaign against the Parthian Empire (162-166)
- Marcus Aurelius campaign against the Marcomanni (171-173)
- Caracalla campaign against the Alemanni (213)
- Gordian campaign against the Sassanid Empire (238)