Legio II Brittannica: one of the legions of the later Roman empire. Its name means, as one may have already guessed, "Second British Legion".
The only source for the exact name of this legion is the text known as Notitia Dignitatum, which is a catalogue of Roman magistracies and military units in the last decade of the fourth century. In other sources the Second British Legion has other names (e.g. Secundani Brittones).
It has been assumed that II Brittannica originated as the mobile part of II Augusta, which later became an independent legion, and was employed in the coastal defense against the Saxons. It is not known when this happened, but perhaps the proud identification of the legion with the country it defended, suggests that it was created in the years 286-297, when Britain was briefly independent under the usurpers Carausius and Allectus.