The LEGO DUPLO theme was introduced as far back as 1969 and is designed for children ages 1 to 5. It features DUPLO figures which are much larger than minifigures and DUPLO blocks which are about twice the length, width, and height of a standard System brick. Like LEGO System, DUPLO also has subthemes that are often junior versions of System themes, like Pirates and Castle and licensed themes like Disney and Super Heros.
1981 LEGO Sets
1981 strengthened the bridge from DUPLO to System through Fabuland, featuring animal characters and story-led builds. Town expanded urban life with new services and vehicles, Space continued its exploration motif with larger craft and surface equipment, and 12V Trains saw ongoing refinements for more sophisticated layouts.