It was a symbol of good luck and good fortune. The Nazis adopted it because they saw the ancient symbol used in India, and by that time it had been known that the Indo-Aryan languages (like Hindi and Sanskrit) are distantly related to most European languages including the Germanic languages (like German and English), all of which are theorized to have descended from a common language about 5,000 years ago called Proto-Indo-European. The Nazis thought Proto-Indo-European was the language of the "Aryan master race", and thought the swastika must have been one of the Aryan symbols.