Castle is a sub-theme in Lego Worlds
The Castle theme present in Lego Worlds is based on a combination of Castle (2007), Kingdoms, and Castle (2013).
Castle (2007) was a theme introduced in 2007. The theme was often referred to as "Fantasy Era" or "Fantasy Castle" by fans to distinguish it from the original Castle theme that was introduced in 1978. The theme ran until 2010, when it was replaced with Kingdoms. The theme mainly focuses on fantasy creatures such as trolls and dwarves, and pits humans against various evil creatures instead of an opposing faction of other human beings. Most sets contained warriors from two opposing factions, in order to increase playability. The first protagonists of the human faction were known as the Crown knights, who fought the Skeleton warriors, led by an Evil Wizard, who appeared in the first year of the theme. In 2008 new foes, the trolls, arose, who were also enemies of the newly added Dwarves. In 2009 only three new sets were released, including 10193 Medieval Market Village which is known to be the most intricate work of European styled buildings ever released by LEGO as an official product. The theme also appears in My LEGO Network as stickers and backgrounds.
Kingdoms is a Castle sub-theme, that was the direct successor to the Castle theme from 2007. It was introduced in mid-2010 and discontinued in early 2012, and the next Castle theme was Castle (2013).
Castle (2013) is a theme that was introduced in 2013, succeeding Kingdoms. It features blue Lion Knights battling red Dragon Knights, and, with both historical and fantastical elements, will combine some aspects of its predecessors, Kingdoms and Castle (2007). It was discontinued in 2015 and replaced by Nexo Knights in 2016.