Spurius Cassius Wecellinus is the first person of the oldest period of the Roman Republic, the existence of which is certified in sources. He took the office of consul three times: in 502, 493 and 486 BCE. According to tradition, during his term in office, he commanded the victorious expeditions against the Sabines, thanks to which he was awarded the title of magister equitum from the dictator Titus Larcius.
He took over the consulate again after the rebellion of the commoners on Aventine Hill. He linked his name to the treaty of the covenant signed between the Romans and the Latins – Foedus Cassianum. The text of the document was stored at the Forum Romanum in the time of Cicero.
During the third consulate, he organized an expedition against Volsci and Hernici, forcing the latter to sign the Roman-Latin agreement. He fought for the plebs to be granted the right to acquire land but met strong resistance from the patriciate.