The Mokshas (also Mokshans, Moksha people, in Мокшет/Mokšet) comprise a Mordvinian ethnic group belonging to the Volgaic branch of the Finno-Ugric peoples. They live in the Russian Federation, mostly near the Volga River and the Moksha River, a tributary of the Oka River. Their native language is Mokshan, one of the two surviving members of the Mordvinic branch of the Uralic language family. According to a 1994 Russian census, 49% of the autochthonal Finnic population in Mordovia identified themselves as Mokshas, totaling more than 180,000 people. Most Mokshas belong to the Russian Orthodox Church; other religions practised by Mokshas include Lutheranism and paganism. William of Rubruck, the Franciscan friar whom King Louis IX of France sent as an ambassador to the Mongols in the 1250s, called them "Moxel". The same term appears in the Persian/Arabic 14th-century chronicle of Rashid-al-Din. According to popular tradition the Russians first used the term "Mordva" to refer only to the Erzya people but later used it for both the Erzyas and the Mokshas. The term "Moksha" ( мокша) begins to appear in Russian sources in the 17th century. Local names for the Mokshas include: Мокшет (Mokšet) or Мокшень ломатть (Mokšeń lomatt́) ("Moksha people") in Moksha Мокшане (Mokshane) or Мордва-Мокша (Mordva-Moksha) in Russian Muqşılar in Tatar Мăкшăсем in Chuvash Мокшот (Mokšot) in Erzya The breakup of the Volga Finns into separate groups is believed to have begun around 1200 BC. The Moksha people cannot be traced earlier because they did not possess a distinctive burial tradition before that time. According to archeological data, bodies in early Mokshan burials were oriented with their heads to the south. Herodotus also describes the Scythian-Persian war of 516-512 BC, which involved the entire population of the Middle Volga. During this war the Sarmatians forced out the Scythians and subdued some Moksha clans. During the 2nd and 3rd centuries AD, Antes, Slavs, Mokshas and Erzyas became the most numerous and powerful population in East Europe.