The German air force unit that bombed the Basque town was popularly known as the Condor Legion. This was composed of volunteer pilots and ground crew and it came to number several hundred. They flew the latest German planes and these were possibly the best airplanes in the Spanish Civil War. The planes were mainly Junkers and they were mainly transport planes. They also had some Dorner DO 17 E1 that the Condor Legion employed in bombing raids. The main plane used by the Condor Legion was the JU 52 and this dropped many of the bombs that were used to devastating effect at Guernica. The Condor Legion also dropped incendiary bombs that caused terrible injuries to civilians. The Condor Legion was used by the Germans to test their aerial capabilities and their tactics. They used Spain as a testing ground for their latest planes and to perfect their ability to conduct bombing raids.