The following year (15 AD) Caecina was involved in the campaign against Arminius, the leader of the Germans who had famously defeated Publius Quinctilius Varus at the Battle of the Teutoburg Forest and destroyed three legions, not including a large number of auxiliaries and camp followers. Germanicus, who first proceeded to attack the Chatti, left him in command of four legions on the Rhine. Caecina was soon forced to turn back a Cherusci advance. He then followed this up with a successful battle against the Marsi. Hearing that Arminius had gathered together a large coalition of forces, Germanicus sent Caecina with forty cohorts towards the Ems as a diversionary tactic, ravaging the countryside as he marched. Rejoining Germanicus, they pushed towards the Teutoburg Forest. Caecina was sent in advance to scout the route, as well as build bridges and causeways so that the army could cross the numerous areas of marshland.