As their name suggests, III Isaura and its twin legion II Isaura were guarding the Isauria territory at the time of the Notitia Dignitatum, to defend it from the incursions of the mountain peoples.
As their name implies, III Isaura and its twin legion II Isaura were safeguarding the Isauria region at the time of the Notitia Dignitatum, to protect it from the invasions of the mountain tribes.