The Sarmatians (/sɑːrˈmeɪʃiənz/; Ancient Greek: Σαρμάται, romanized: Sarmátai; Latin: Sarmatae [ˈsarmatae̯]) were a large confederation of ancient Iranian equestrian nomadic peoples who dominated the Pontic steppe from about the 5th century BC to the 4th century AD.
The earliest known reference to the Sarmatians occurs in the Avesta, where they appear as Sairima-, which in later Iranian sources becomes Sarm and Salm. Originating in the central parts of the Eurasian Steppe, the Sarmatians formed part of the wider Scythian cultures. They started migrating westward around the fourth and third centuries BC, coming to dominate the closely related Scythians by 200 BC. At their greatest reported extent, around 100 BC, these tribes ranged from the Vistula River to the mouth of the Danube and eastward to the Volga, bordering the shores of the Black and Caspian seas and the Caucasus to the south.