An Escort Group consisted of several small warships organized and trained to operate together protecting trade convoys. Escort groups were a World War II tactical innovation in anti-submarine warfare by the Royal Navy to combat the threat of the Kriegsmarine's "wolfpack" tactics. Early escort groups often contained destroyers, sloops, naval trawlers and, later, corvettes of differing specifications lacking the ability to maneuver together as a flotilla of similar warships, but rigorously trained in anti-submarine tactics to use teamwork emphasizing the unique sensors, weapons, speed, and turning radius of each ship. The development of these 'escort groups' proved an effective means of defending shipping convoys through the Battle of the Atlantic.