Sebbirozi
The Sebbirozi was a tribe mentioned by the 9th-century Bavarian Geographer ({{abbreviation|BG|Bavarian Geographer}}). It states that the Sebbirozi inhabit 90 settlements (Sebbirozi habent civitates XC).{{cite book|author=Christian Lübke|title=Das östliche Europa|url=https://books.google.com/books?id=mFJpAAAAMAAJ|year=2004|publisher=Siedler|page=22|quote=Die Sebbirozi haben 90 Burgen.}}
Linguist Aleksander Brückner related Sebbirozi with another tribe from the source, Zabrozi, deriving from Proto-Polish *sebr (Old Polish siebr and siabr, or szabr), transcribing to what he believed as true names *sebracy and *siabracy.{{cite book|last=Brückner|first=Aleksander|authorlink=Aleksander Brückner|title=Studja staropolskie: księga ku czci Aleksandra Brücknera|url=https://books.google.com/books?id=YAsDAAAAMAAJ|year=1928|publisher=Nakł. Krakowskiej spólki wydawniczej|language=pl|pages=54–55}} Historian Henryk Łowmiański and linguist Stanisław Rospond connected the ethnonym to the Severians,{{cite book|author=Henryk Łowmiański|title=Studia nad dziejami Słowiańszczyzny, Polski i Rusi w wiekach średnich|url=https://books.google.com/books?id=y-dBAAAAYAAJ|year=1986|publisher=Uniwersytet im. Adama Mickiewica w Poznaniu|pages=161–169}}{{cite journal |last=Łuczyński |first=Michal |date=2017 |title="Geograf Bawarski" — nowe odczytania |trans-title="Bavarian Geographer" — New readings |url=https://rcin.org.pl/dlibra/show-content/publication/edition/64469?id=64469 |language=pl |journal=Polonica |volume=XXXVII (37) |page=74 |doi=10.17651/POLON.37.9 |access-date=5 August 2020|url-access=subscription }} while the others to the Sabirs.{{cite book|editor=Władysław Kowalenko|title=Słownik starożytności słowiańskich: encyklopedyczny zarys kultury słowian od czasów najdawniejszych|url=https://books.google.com/books?id=p7RmAAAAMAAJ|year=1975|publisher=Polska Akademia Nauk. Komitet Słowianoznawstwa, Zkład Narodowy im. Ossolińskich|language=pl|page=178}} More recently, Krzysztof Tomasz Witczak also treats the Sebbirozi as one of the five Turkic tribes from the source, precisely the Sabirs. Already in 1958 Łowmiański considered etymological and geographical relation between the Sebbirozi, Attorozi, Uuillerozi, Zabrozi, Chozirozi due to unusual non-Slavic, yet Turkic suffix -rozi. The Attorozi themselves are described as populus ferocissimus.{{cite journal |author=Krzysztof Tomasz Witczak |title=Poselstwo ruskie w państwie niemieckim w roku 839: Kulisy śledztwa w świetle danych Geografa Bawarskiego |url=https://www.academia.edu/6870884/A_Russian_Mission_to_the_German_East_Frankish_State_in_839_in_Polish_English_Summary_ |year=2013 |journal=Slavia Orientalis |volume=62 |issue=1 |language=pl, en |pages=37, 39, 42}}