Which Greek Stoic philosopher mentioned two of the four subgroups of the Helvetians that failed in their migration attempt to Gaul?
Helvetii The Helvetii (Latin: "Helvētiī" ] ) were a Gallic tribe or tribal confederation occupying most of the Swiss plateau at the time of their contact with the Roman Republic in the 1st century BC. According to Julius Caesar, the Helvetians were divided into four subgroups or "pagi." Of these Caesar only names the Verbigeni and the Tigurini, while Posidonius mentions the Tigurini and the Tougeni (Τωυγενοί ). They feature prominently in the "Commentaries on the Gallic War," with their failed migration attempt to southwestern Gaul (58 BC) serving as a catalyst for Caesar's conquest of Gaul.
Spali The Spali (Latin: "Spalaei, Palaei" ) was a tribe mentioned by Pliny (23–79) and Jordanes ( 551), located in the region south of Kiev. They are believed by some (Tadeusz Sulimirski) to have been a branch of the Roxolani. Sulimirski attributed Sarmatian archaeology on the mid-Dnieper to the tribe, supported by the Sarmatians' downfall after the Gothic invasion in 200 AD. Another connection is made to the "Royal Sarmatians" (mentioned by Strabo as a Scythian tribe, also called "Ourgoi"), supported by Indo-Parthian royal names "Spalirisos", "Spalyris", "Spalahora", and the Slavic word "ispolin", "spolin" ("giant"), assumed to date back to when the Slavs were ruled by the Spali.