Lakota, Nakota, Dakota

The Siouan Language family is quite extensive, and covers a wide area with many sub-groups and dialects as seen in the diagram below.

Speaking the same or similar root language did not guarantee that there would not be curtural or political differences that often turned to rivalries or violent clashes.
 
The Siouan family consists of 17 languages with various sub-languages:
 
  I. Missouri River Siouan (a.k.a. Crow-Hidatsa)
        1. Crow (a.k.a. Absaroka, Apsaroka, Apsaalooke, Upsaroka)  
        2. Hidatsa (a.k.a. Gros Ventre, Minitari, Minnetaree)  
 
 II. Mandan Siouan
         3. Mandan  
             a. Nuptare  
             b. Neutare
 
III. Mississippi Valley Siouan (a.k.a. Central Siouan)
 
     A. Dakotan (a.k.a. Sioux-Assiniboine-Stoney)  
         4. Sioux  
             a. Santee (a.k.a. Eastern Sioux, Dakota)  
                 i. Mdewakanton  
                ii. Wahpekute
               iii. Sisseton
               iv. Wahpeton    
             b. Yankton (a.k.a. Central Sioux, Nakota)  
                 i. Yankton  
                ii. Yanktonai  
             c. Teton (a.k.a. Western Sioux, Lakota)  
                 i. Sicangu  
                ii. Itazipco
               iii. Sihasapa
               iv. Mnicoujou
                v. Oohenumpa
               vi. Oglala
              vii. Hunkpapa
         5. Assiniboine (a.k.a. Assiniboin)  
         6. Stoney (a.k.a. Alberta Assiniboine)  
 
     B. Chiwere-Winnebago (a.k.a. Chiwere)  
         7. Chiwere (a.k.a. Ioway-Otoe-Missouria, Ioway-Otoe)  
             a. Iowa (a.k.a. Ioway)  
             b. Otoe (a.k.a. Oto, Jiwere)  
             c. Missouria (a.k.a. Missouri)  
         8. Winnebago (a.k.a. Hocák, HoChunk, Hochank, Hocangara, Hotcangara, Hochangara)  
     
     C. Dhegiha (a.k.a. Dhegihan)  
         9. Omaha-Ponca  
             a. Omaha  
             b. Ponca (a.k.a. Ponka)  
       10. Kansa-Osage  
             a. Kansa (a.k.a. Kanza, Kaw) (†)  
             b. Osage  
       11. Quapaw (a.k.a. Kwapa, Kwapaw, Arkansas) (†)  
 
IV. Ohio Valley Siouan (a.k.a. Southeastern Siouan)
 
     A. Virginia Siouan
       12. Tutelo  
       13. Saponi (a.k.a. Saponey) (†)  
       14. Moniton (a.k.a. Monacan) (†)  
       15. Occaneechi  
 
     B. Mississippi Siouan (a.k.a. Ofo-Biloxi) (†)  
       16. Biloxi (†)  
       17. Ofo (a.k.a. Ofogoula) (†)  
 
(†) - Extinct language