A Latin phrase; literally, "by fire and sword". Back in the days of the Roman Empire, a Writ of Igne Ferroque would be given to commanders given them authority to drive out a population by any means necessary -- in other words, through a destructive and terrorist raid on the area.
The same phrase was later used in Scottish law to give a sheriff the authority to evict people using any available means. It is also part of the emblem of England's 404th Fighter Group, Air Force, which played an active part in World War II as a dive bombardment unit. (The complete motto is "Igne ferroque hostem armatum contere," or "with fire and steel crush the armored foe.")