LEGO Castle is the theme introduced in 1978 focusing on medieval castles, knights and royal heraldry.
The first LEGO Castle sets established the visual language that defined the theme for decades: fortified walls, towers, drawbridges, shields, swords and horse-mounted knights. Minifigures allowed the medieval setting to become a character-driven play world rather than only a collection of buildings.
Different factions appeared over time, including the classic Lion Knights, Black Falcons, Black Knights and Forestmen. Their shields and flags often carried distinct heraldic symbols, helping children identify allies and rivals during play.
LEGO Castle is an original LEGO theme, not a direct adaptation of one specific historical kingdom. Later versions introduced fantasy elements such as dragons, wizards and skeletons. That mixture of broadly medieval architecture and fantasy storytelling is why Castle is sometimes grouped with LEGO's historical themes, even though many sets were deliberately imaginative rather than historically exact.