The Zealots were the armed resistance to the Roman occupation of Israel, and caused uprisings throughout a 200 year period. They terrorized collaborators, assassinated leaders, robbed caravans and killed legionaries whenever they could, operating as urban and rural guerrillas with their trademark curved dagger, the sica. They were sicariots, dagger men.
The Romans called them sicariots, robbers, thieves and brigands. But they would hardly call them heroes, patriots and freedom fighters, would they?
Once a generation or so a Zealot leader would arise who would lead a full-scale revolt – capture a city, massacre gentiles, loot arms and treasure, and finally be crushed when the Romans sent in a couple of Legions.
In 6 CE when Jesus was about 12, Judas of Galilee captured Sepphoris (or Zippori), the capital of Galilee only four miles from Nazareth. The Romans defeated his ragtag forces and crucified 2,000 of them. (Jesus’ father Joseph is not heard of after that event.)
After Jesus led his unsuccessful uprising in the Temple at Jerusalem, he was caught and crucified between two “thieves”. Neither theft nor blasphemy was punished with crucifixion; only rebellion was. When the Romans labeled Jesus “King of the Jews” they were echoing his claim from his ride into Jerusalem on his donkey, and clarifying why they were crucifying him. The two “thieves” were also important enough to be crucified.
A fourth was arrested and released: Barabbas, identified as “a robber”. “Bar-abbas” is a strange name – it means “son of a father”, “son of his father”, or “Son of the Father”. He was a Zealot, anyway. In “The Gospel According to the Romans” I suggest a couple of different reasons for his release.
The Zealots were active for another 100 years, until the final destruction of Jerusalem in the Bar Kokhba Revolt.