Waldorf schools originated in Germany in the early 1900s and were developed to provide education for factory workers. The schools used a curriculum developed by Rudolf Steiner based on the philosophy of anthroposophy, which viewed spiritual, physical and mental development as interconnected. Waldorf education has three stages - ages 0-7 focus on imagination, ages 7-14 on developing literacy while keeping students with the same teacher, and ages 14-21 on abstract thinking, ethics and career preparation. Some key principles include an emphasis on art, music, outdoor activities and storytelling, and keeping early education simple and experiential. Over time Waldorf schools spread internationally but faced challenges under Nazi rule in Germany.