Arminius' revolt came during the Pannonian revolt, at a time when the majority of Rome's legions were tied down in Illyricum. Varus only had three legions, which were isolated in the heart of Germany. Scouts were sent ahead of Roman forces as the column approached Kalkriese. Scouts were local Germans as they would have had knowledge of the terrain, and so would had to have been a part of Arminius' ploy. Indeed, they reported that the path ahead was safe. Wells and Abdale say that the scouts likely alerted the Germans to the advancing column, giving them time to get into position.