The word Siouan means "related to the Sioux" and it mostly a linguistic term. The language our people spoke was not a mirror image of the languages spoken by the Lakota, Dakota, and Nakota peoples, but shared many similarities with them as far as certain words, verb usage, sentence structure, and grammatical idiosyncrasies. The works of authors like James Mooney, Edward Alexander, Edward Sapir, Leo Frachtenberg, Horatio Hale and other linguists have proven that the Tutelo-Saponi language is a Siouan dialect and a multitude of authors and researchers have traced the migration of the Saponi from the Ohio River Valley, very near the historical and traditional homelands of the Sioux, to the Piedmont area of Virginia and North Carolina.
There are legends that have been passed down from Sioux Elders that say that the Saponi were "those who went hunting and never returned" and there are some similarities between the artefacts familiar to the Wamnuga Owin (Cowrie Shell Earings or Shell ear ornaments or pendants) band of the Siha Sapa (Blackfoot Sioux) and artefacts found among the Saponi and their predecessors that were made out of shells, like the gorgets found at the Fredericks and Wall archeological sites - though this connection is, at present, pure speculation, it is tentatively supported by the fact that the Saponi were often called "The Eastern Sioux" or "Eastern Blackfoot".
It is reasonable to assume that in distant antiquity, we were one people. At some unknowable time in the past, our people traveled East into the Ohio River Valley and then again into the Piedmont. Very likely, this migration was the result of pressures created by the Iroquois, as that confederacy of tribes had been focused on building their influence and strength in the area - a goal which pursued our people until a portion of our people were accepted into the Six Nations at the Great Council Fire of 1753. The Saponi were far from the only Siouan speakers, however, and shared this trait with several of our neighbors. Among the Siouan speakers of the Piedmont, we find very distinct "dialects", if you will - Ohio Valley Siouan, Missouri River Siouan, Mississippi Valley Siouan, and Mandan which is rather stand alone. Among the Ohio Valley Siouan speakers were the Saponi-Tutelo, Moneton, Monacan, Occaneechi, Biloxi, and Ofo. Because we shared linguistic similarities, as well as proximity in our tribal ranges, it is safe to assume some cultural crossover as well.
The Catawba people, whom our nation is partially named for, is an interesting outlier. Linguistically, the Catawba spoke a Mississippi Valley dialect of Siouan, but the Saponi spent much time with the Catawba, and lived with and intermarried with them both prior to the founding of and the abandonment of Fort Christanna. The historical record reminds us that the Seneca ambushed a party of visiting Catawba outside the gates of Fort Christanna around 1718. Not long after, a Saponi chief was hung for allegedly killing a colonist and the Saponi withdrew from Fort Christanna to Catawba lands. During this time, there were intermarriages and adoptions, and it is for this reason that the Saponi-Catawba Nation is so named - to reflect the ancestral heritage of our forbears.