A triumph was gained also over the outer foe. The Syrian legate, Cestius Gallus, appeared before Jerusalem in the autumn of 66, but after a short period raised the siege; his deliberate withdrawal was changed into a precipitate flight in an attack made by the Jews at Bethhoron. The revolt now spread irresistibly through all ranks and classes of the population, and the aristocracy found it expedient itself to assume the leadership. An autonomous government was organised, with the noblest members of the community at its head; of these the most important was the high priest Ananus.
Meanwhile Nero entrusted the conduct of the Jewish war to Vespasian, his best general. In the spring of 67 he began his task in Galilee, where the historian Josephus had command of the insurgents. The Jews entirely distrusted him and he them; in a short time the Romans were masters of Galilee, only a few strong places holding out against them. Josephus was besieged in Jotapata, and taken prisoner; the other places also were unable to hold out long. Such of the champions of freedom in Galilee as escaped betook themselves to Jerusalem; amongst these was the Zealot leader John of Giscala. There they told the story of their misfortunes, of which they laid the blame upon Josephus, and upon the aristocratic government as having no heart for the common cause and having treachery for their motto. The Zealots now openly aimed at the overthrow of the existing government, but Ananus bravely withstood them, and pressed so hard on them that they summoned the Idumaeans into the city to their aid. These honourable fanatics indeed withdrew again as soon as they had discovered that they were being used for sinister designs; but in the meanwhile they had accomplished the work of the Zealots. The old magistracy of Jerusalem was destroyed, Ananus with the heads of the aristocracy and very many other respectable citizens put to death. The radicals, for the most part not natives of the city, came into power; John of Giscala at their head tyrannized over the inhabitants.