Ninja was a Castle subtheme from 1998 to 2000 and the first time the theme left medieval Europe, for feudal Japan. Its sets had ninja, samurai, a shogun in his stronghold and a band of robbers, with secret doors, hidden weapons and booby traps in the buildings. 6093 Flying Ninja Fortress was the largest set. The line ended in 2000 with minifigure packs. The ninja minifigures brought new headgear and weapons that LEGO used for years after. The idea came back on a much larger scale in 2011 with Ninjago, a theme of its own.
2000 LEGO Sets
2000 was a year of transition and innovation for LEGO. The company introduced RoboRiders, Knights’ Kingdom, Life on Mars, Studios, and a Soccer/Football theme while retiring veteran designer Jens Nygaard Knudsen, creator of the minifigure. Star Wars launched its first Ultimate Collector Series sets—the X-wing Fighter (7191) and TIE Interceptor (7181)—establishing LEGO’s adult collector market. BIONICLE debuted in select regions, setting the stage for a major global launch. Recognized as 'Toy of the Century,' the LEGO brick entered the new millennium as both a cultural icon and a growing creative platform.