If you see the term "Dorian" it will probably be in connection with the Dorian Invasion, a legendary event that drove Greeks (Hellenes [see next section]) from mainland Greece to settle in Asia Minor. There these Hellenes became known as Ionians. The Spartans are referred to as Dorians.
Legendary Origins of the Dorians
Deucalion, a mortal, and the son of Prometheus, was the father of Hellen, after whom the Hellenes, whom we call Greeks, were named. Hellen had three sons, Dorus, Xuthus, and Aeolus. Dorus was the eponymous founder of the Dorians. Achaeus, eponymous founder of the Achaeans is the son of Xuthus. Aeolus, was an ancestor of Neleus, the founder of Miletus.
Source - Strabo as a Source of Local Myth [http://apaclassics.org/images/uploads/documents/abstracts/patterson.pdf].
"[7.3] Hellen had Dorus, Xuthus, and Aeolus by a nymph Orseis. Those who were called Greeks he named Hellenes after himself, and divided the country among his sons. Xuthus received Peloponnese and begat Achaeus and Ion by Creusa, daughter of Erechtheus, and from Achaeus and Ion the Achaeans and Ionians derive their names. Dorus received the country over against Peloponnese and called the settlers Dorians after himself. Aeolus reigned over the regions about Thessaly and named the inhabitants Aeolians. He married Enarete, daughter of Deimachus, and begat seven sons, Cretheus, Sisyphus, Athamas, Salmoneus, Deion, Magnes, Perieres, and five daughters, Canace, Alcyone, Pisidice, Calyce, Perimede."
~ Apollodorus Library
