Tsukushi (former province)
Historical province in northern Kyūshū, later divided into Chikuzen and Chikugo. Used in historical contexts.
Tsukushi was an ancient province in northern Kyūshū.
Kyūshū (archaic)
Archaic name for the entire island of Kyūshū. Rarely used in modern Japanese outside historical or literary references.
See also: 九州
In old documents, the whole of Kyūshū is sometimes called Tsukushi.
The name 筑紫 (Tsukushi) is of ancient origin, predating the division into Chikuzen and Chikugo. The exact derivation is uncertain, but it has been used since early Japanese history to refer to the northern part of Kyūshū.