Due to the First Jewish-Roman War, the destruction of the Second Temple ushered in a major time of dramatic reformation in religious leadership, causing the face of Judaism to change. The Second Temple served as the centralized location from which the ruling groups Sadducees and the Pharisees maintained Judaism, with rivaling Essenes and Zealots being largely in opposition. With the destruction of the temple, the major ruling group lost their powerthe Sadducees, who were the priests, directly lost their localized power source and were rendered obsolete. Due to this, only one group was left with all the powerthe Pharisees, who were the rabbinic group. The rabbinic groups' power did not derive from the temple or from military prowess, which enabled their power to spread among synagogues to different communities. This changed the way Judaism was practiced on a daily basis, which included changing from sacrificing animals to praying in order to worship God. Rabbinic Judaism became a religion centered around synagogues, and the Jews themselves dispersed throughout the Roman world and beyond. With the destruction of Jerusalem, important centers of Jewish culture developed in the area of Galilee and in Babylonia and work on the Talmud continued in these locations. Before Vespasian's departure, the Pharisaic sage and Rabbi Yohanan ben Zakkai obtained his permission to establish a Judaic school at Yavne. Zakkai was smuggled away from Jerusalem in a coffin by his students. This school later became a major center of Talmudic study (see Mishnah).