Onomastic evidence for the identification of the Asii and Alans is provided by later medieval European scholars and travellers. In the 13th century, Giovanni da Pian del Carpine ("Johannes de Plano Carpini") referred to "Alani sive Assi" ("Alans or Assi") and William of Rubrouck used the name "Alani sive Aas" ("Alans or Aas"). In the 15th century, Josephus Barbarus reported that the Alans referred to themselves by the name "As". The name of the Ossetians, who are descended from the Alans, also has its root in the alternate ethnonym "Osi".