First Official Ashkenazi Chief Rabbi of then British-controlled Palestine, (a position which was later succeeded by that of Chief Rabbi of Israel), established the foundation of the Chief Rabbinate of Israel , the Rabbanut, and Israel's national rabbinical courts , Batei Din that work in co-ordination with the Israeli government, having jurisdiction over much law relating to marriage, divorce, conversion,and education.
Built bridges of communication and political alliances between the secular Jewish Zionist leadership and believers of Religious Zionism. He believed, according to his theological system , that the youthful, secular and even anti-religious , labor Socialist pioneers halutzim were actually part of a grand divine scheme whereby the land and people of Israel were finally being redeemed from the 2,000 year exile (galut) by all manner of Jews who sacrificed themselves for the cause of building up the physical land, as laying the groundwork for the ultimate spiritaul messianic redemption of world Jewry.
His empathy towards the anti-religious elements aroused the suspicions of his more traditionalist haredi opponents,particularly that of the old-time rabbinical establishment that had funtioned from the time of Turkey 's control of greater Palestine, whose paramount leader was Rabbi Yosef Chaim Sonnenfeld, Rabbi Kook's greatest rabbinical rival.
Ulumnas of the famous yeshiva of Volozhin , scholar of Talmud and kabbalah and author of far ranging works on Jewish thought and mysticism