Dalemark is the setting for a group of four early Diana Wynne Jones novels: The Dalemark Quartet. It is a country at the edge of a sea, and is politically divided into North Dalemark and South Dalemark. In addition there are various islands that are part of neither group.
The quartet of novels describes events in this country at three different periods of history, telling each story with a focus on a single protagonist within a family. Each family operates within the context of the country at that period of time, but the events they deal with resonate with novels either before or after them.
Dalemark is a land that resembles medieval Britain or Westernmost Europe. It is run by various Earls, lords, or kings, and writing is done in runes. People raise sheep and weave woolen cloth, cherish household idols, and fight with swords, spears, or longbows. Magic is widespread.