Other important factions were the Pharisees, the Sadducees, the Essenes and the Christians.
One particularly extreme group of Zealots was also known in Latin as sicarii, "daggermen" (sing. sicarius), because of their policy of assassinating Jews opposed to their call for war against Rome. Some have speculated that the name of Jesus' disciple Judas Iscariot is a corruption of this term - "Judas the Zealot".
The Zealots were opposed to Roman rule and sought to eliminate it by violent means. At the time of Jesus Christ their activities were limited to raids on Jewish settlements and eliminating Jewish collaborators (tax collectors, like Matthew, were often collaborating with the Romans)
Among the Apostles of Jesus, there were two possible Zealots, Judas Iscariot and Simon the Canaanite, also known by Luke as Simon the Zealot.
The Zealots had the leading role in the Jewish Revolt of CE 66. They succeeded in taking Jerusalem, and held it until 70, when the son of Roman emperor Vespasian, Titus Flavius, recaptured the city and destroyed the Second Temple.
One of their leaders, Eleazar bin Jair managed to escape to the desert fortress of Masada and fought alongside the Sicarii Zealots until the Masada was captured in 73.
The Jewish Revolt was quickly suppressed and the Zealots lost all their influence and finally vanished.