The Seduni were a Gallic tribe dwelling in the upper Rhône valley, around present-day Sion, during the Iron Age and the Roman period.
Along with the Nantuates, Veragri and Uberi, they were part of the Vallenses, a group of tribes living between Lake Geneva and the Pennine Alps, in the modern Canton of Valais (Switzerland).
[4] Pierre-Yves Lambert has also proposed to analyze the name as a haplology (loss of syllable) for *Se(go)-dunum ('the strong fortress').
Even though Sedunum lost its political importance in the mid-1st century AD, when Forum Claudii Vallensium (Martigny) became the capital of the civitas Vallensium, the location remained a popular place of residence for notables: funerary stelae attest to the presence of duumviri (magistrates of the civitas), flamines (priests of the imperial cult), a Roman knight, a former consul, and, by the 4th century, praesidia (governors of the province).
[2] They are mentioned by Pliny the Elder as one of the Alpine tribes conquered by Rome in 16–15 BC, and whose name was engraved on the Tropaeum Alpium.