Siouan languages
In the 19th century, Robert Latham suggested that the Siouan languages are related to the Caddoan and Iroquoian languages. In 1931, Louis Allen presented the first list of systematic correspondences between a set of 25 lexical items in Siouan and Iroquoian. In the 1960s and 1970s, Wallace Chafe further explored the link between Siouan and Caddoan languages. In the 1990s, Marianne Mithun compared the morphology and syntax of all the three families. At present, this Macro-Siouan hypothesis is not considered proved, and the similarities between the three families may instead be due to their protolanguages having been part of a sprachbund.
Sioux
The Sioux people refer to the Great Sioux Nation as the Očhéthi Šakówiŋ (pronounced ), meaning "Seven Council Fires"). Each fire is a symbol of an oyate (people or nation). Today the seven nations that comprise the Očhéthi Šakówiŋ are the Thítȟuŋwaŋ (also known collectively as the Teton or Lakota), Bdewákaŋthuŋwaŋ, Waȟpéthuŋwaŋ, Waȟpékhute, and Sisíthuŋwaŋ (also known collectively as the Santee or Eastern Dakota) and Iháŋkthuŋwaŋ and Iháŋkthuŋwaŋna (also known collectively as the Yankton/Yanktonai or Western Dakota). They are also referred to as the Lakota or Dakota as based upon dialect differences. In any of the dialects, Lakota or Dakota translates to mean "friend" or "ally" referring to the alliances between the bands.