It came with six minifigures two archers, two spearmen, and two knights mounted on horses. In 1984, the first Black Falcons castle was 6073 Knight's Castle. Although the term Black Falcons wasn't explicitly and internationally used to market the faction in its original incarnation, Lego later picked up the term in its own marketing to refer to the earlier theme. However, the faction was never labeled as anything other than 'Castle', nor was it ever officially recognized as a theme. A 1989 US catalogue includes an ambiguous reference to the 'Guardians of the Gray Castles'. Some fans in the United States have labeled this faction as 'Black Falcons', and Australian fans have called them 'Eagle Crest', though at the time each term only appears once in any official Lego literature – both in regional names for set 6074. The minifigures that were associated with this symbol almost invariably had black pants, black helmets, and blue torsos with black sleeves, often with the bird emblem on their chests and shields (with a blue or gold border). The sets that were released during this time period predominantly featured the motif of a black and white bird against a black and white background, split down the middle. The 1990 castle sets brought a further changes – as knights now had armor breastplates and helmets with movable visors. Many of these new pieces would be included in future castle sets. Examples are: one-piece horse, horse saddles, new knight helmets with fixed visors, feather plumes (there were three types in five colors: red, blue, yellow, white and black), waving flags and bows and arrows. The 1984 castle sets featured many newly introduced pieces and weapons. In 1984, Lego released the first Castle sets that had more realistic castles, knights, and colors (such as gray castles rather than yellow) that more accurately depicted the Middle Ages compared to the Classic Castle sets from the late 1970s and early 1980s. As there were no horse-specific pieces, horses were built entirely of bricks. It was not again until 1990 when knights came with movable visors and armor breastplates, as the knights between 19 had solid grill helmets while their 'armor' was just a texture on their body. These knights also wore a coat of arms (either a tunic or breastplate) over their body.

Often known by fans as 'Original Castle', the knights featured unique movable visor pieces, with eye slits, and a crest that runs backwards from the frontward-facing part of the visor along the helmet. 375 Castle (often called the Yellow Castle) is the most well known set from this time. The Castle period from 1978 to 1983 predates themes or factions, and is often known as 'Classic' Castle. 'Classic' Castle (1978–1983) Assembled vintage 1978 Legoland 375 (the 'Yellow Castle') Lego decided to change and add Lego System in 1992. Lego Castle sets were marketed under the Legoland banner until 1991. Other medieval Lego themes have included Knights Kingdom, Knights Kingdom II, and Kingdoms, and are included here. It was also the name of a Lego theme within that environment from 1987 to 1991, and the name was reused for two other, single-theme environments, one from 2007 to 2009 and the other in 2013. It was introduced in Europe in 1978 and North America in 1981, and was supported continuously until 1999. Lego Castle was a Lego medieval and fantasy environment featuring knights and castles.

Lego medieval figures