|Isaiah Berlin and his wife Aline, Oxford, 1969; photograph by Dominique Nabokov|
Yeshayeh Berlin was not only a follower of Chabad chassidism and a leading backer of the fifth rebbe of Chabad-Lubavitch, Rabbi Shalom DovBer Schneersohn (Rashab), in his battle to combat acculturation and preserve traditional Jewish life. Yeshayeh Berlin was also married to the Rebbe's first cousin, Chayetta. Both were grandchildren of the third rebbe of Chabad-Lubavitch, Rabbi Menachem Mendel Schneersohn (the Tzemach Tzedek). Chayetta's sister Frumma was Isaiah Berlin's great grandmother.
In short, the Berlins of Oxford were descendants of two opposing ideological factions within the uppermost the philanthropic Jewish aristocracy of Tsarist Russia. Despite the ideological opposition the Schneersohns and Berlins maintained cordial relationships with the de Gunzbourg family, and worked together with them on economic and humanitarian projects of mutual interest. One example, which I wrote about here, was the Chinese matzah campaign of 1905. Although Baron Horace de Gunzbourg initially declined Rabbi Shalom DovBer's plea for help in this endeavor, the latter latter suggested that the former's son, Baron David de Gunzbourg be invited to chair the campaign committee.
Isaiah Berlin was well aware of his illustrious chassidic lineage, but not at all acquainted with the intellectual and cultural riches of his chassidic heritage. His father, Mendel, fled to London following the communist takeover of Russia, but remained well connected with the Chabad leadership until his parents and inlaws were murdered following the Nazi conquest of Riga, circa 1941.
Berlin himself appears to have met the sixth Rebbe of Chabad, Rabbi Yosef Yitzchak Schneersohn, while in Marienbad in the Summer of 1933 (see Isaiah Berlin,Letters Vol 1. [1928-1946], page 56, and Rabbi Yosef Yitzchak Schneersohn, Igrot Kodesh Vol. 3, page 43). In the aftermath of World War Two and the holocaust the family connection was eroded, and Isaiah's impressions of chassidism were too distant and superficial for him to pursue any remaining ties. But Mendel still looked back to the heyday of the Berlin family with nostalgia. In an eighty-six page manuscript dating from 1946 (held today by the Bodleian Library at Oxford, MS. Berlin 819 and MS. Berlin 820) he transcribed his own history, and the history of his chassidic forebearers. He also called upon his son to renew his connection with his roots, apparently to little avail.
For more on the history of the Berlin family see the first chapters of Isaiah Berlin: A Life by Michael Ignatieff.
The following is an abstract of my related article, reflecting a dialogue between Berlin's essay The Hedgehog and the Fox and Chabad thought, as recently published in Hakirah:
Identity and meaning hang upon the balance that must be struck between the two poles of unity and multiplicity. According to Isaiah Berlin this existential dilemma lies at the heart of Tolstoy’s great epic, War and Peace. All people that are not superficial believe in some kind of cohesive vision. But when the threads of life start to unravel even the wisest of men may be rendered mute. In The Gate of Unity and Faith Rabbi Schneur Zalman of Liadi expands the quintessence of faith into the circle of reason, and fits the square of dissonance into the circle of life.See also this related article by Rabbi Eli Brackman of Chabad at Oxford University: The convergence of the philosophy on liberty of Sir Isaiah Berlin and the Lubavitcher Rebbe.