Lucus is Lucalis's alternate timeline where
- The Arabs never conquered Persia, but discovered the Americas, or Almarevia, instead. They also gained permanent footholds in Iberia.
- In 1066, Harold Hardrada of Norway conquered Northumbria, and William of Normandy conquered southern Ingland, while an Anglian aristocratic republic arose as a buffer zone in the Midlands.
- The Hundred Years War was about the Northern English driving out the Normans, and about the kings of France trying to gain control over their nominal vassals. France eventually regained Normandy, but permanently lost Borgonze.
- The Norse actually colonized Vinland
The adjective for 'belonging to Lucus' is Lucal.