Lore
The lore of Wesnoth is primarily in the story of the mainline campaigns. Additionally, secondary information about the units, factions, and races are available in the in-game help.
History
Main article: Timeline of Wesnoth
The history of Wesnoth uses the "YW" ("Years Wesnoth") calendar, where events taking place before the founding of Wesnoth are in years that are counting down and described as "BW" ("Before Wesnoth"), while events afterward are in years that are "YW" and counting up. There is no year zero. The Rise of Wesnoth (TRoW) is a campaign that takes place primarily in the BW years while most other campaigns are given YW dates. The far future does not use this calendar system.
The events concerning Wesnoth mostly take place between 12 BW (right before the 5 BW start of TRoW) and 858 YW (when Son of the Black-Eye ends).
One of the most central campaigns to the history of Wesnoth, Heir to the Throne (HttT), takes place 517-518 YW.
Another pivotal period for Wesnoth is depicted in Eastern Invasion, which takes place 625-627 YW, when the lich Mal-Ravanal invades Wesnoth.
Multiplayer
The multiplayer Default Era and its factions are roughly from around the HttT time period of history (circa 500-550 YW). However, the Default Era (besides some of the faction names) should mostly still apply for the entire covered YW time span of 1 to 858 YW. The Default Era is especially applicable for the broad 350-700 YW period of history where most of the mainline campaigns take place.
The far future, as depicted in Under the Burning Suns, does not use the same units or factions as the Default Era. These units are not available in a mainline multiplayer era.
Geography
Main article: Geography of Wesnoth
The geography of the game The Battle for Wesnoth takes place almost entirely on a planet called Irdya and most campaigns take place on the Great Continent, in the areas in and surrounding the Kingdom of Wesnoth. The Great Continent is never pictured in its entirety and Wesnoth is located on the west coast of the Great Continent toward the north, but not in the far north.
Notable Figures
Main article: WesnothFigures
The main people of note are the protagonists and antagonists of the mainline campaigns.
Haldric I is the founder of the Kingdom of Wesnoth, as depicted in the Rise of Wesnoth. Konrad is a prince of the kingdom of Wesnoth five centuries later, as depicted in Heir to the Throne.