Historians seek to understand where Jesus and his followers fit among other Jewish factions at the time. According to the Jewish-Roman historian Flavius Josephus, the three parties in contemporary Judaism were the Pharisees, the Sadducees and the Essenes, the last of these three being apparently marginalized and in some cases retired to quasi-monastic communities. Josephus also speaks of a "Fourth Movement", Zealots, Lestai or Sicarii.