Rabbi Shalom Sharabi, known by his name's acronym, the RaShaSH, was born in Yemen, and as a young man immigrated to Israel. He was quickly recognized for his piety and scholarship, especially in the area of Jewish mysticism, and was appointed to be dean of the famed Kabbalistic learning center in the Old City of Jerusalem, the Yeshivat ha-Mekubbalim.
He authored many works, mostly based on the teachings of the great kabbalist, Rabbi Isaac Luria, the Ari. Rabbi Sharabi's most famous work is a commentary on the prayerbook, replete with kabbalistic meditations.
His mystical works are studied by kabbalists to this very day. He is also considered to be a foremost authority on Yemenite Jewish traditions and customs.
Link: What Is Kabbalah
Rebbetzin Rivkah Schneerson was born in Lubavitch in 1833; her maternal grandfather was Rabbi DovBer, the 2nd Rebbe of Chabad-Lubavitch. In 1849 she married her first cousin, Rabbi Shmuel, who later became the fourth Lubavitcher Rebbe. For many years Rebbetzin Rivkah, who survived her husband by 33 years, was the esteemed matriarch of Lubavitch, and Chassidim frequented her home to listen to her accounts of the early years of Lubavitch. She is the source of many of the stories recorded in the talks, letters and memoirs of her grandson, Rabbi Yosef Yitzchak (the sixth Lubavitcher Rebbe). The Beth Rivkah network of girls' schools, founded by Rabbi Yosef Yitzchak in the 1940's, is named after her.
Links:
Watch a video about Rebbetzin Rivkah
Read a story of the great-grandfather of Rebbetzin Rivkah
The sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneersohn, passed away on Shabbat morning, the 10th of Shevat, of the year 5710 from creation (1950)
At a gathering of Chassidim marking the first anniversary of the passing of the sixth Lubavitcher Rebbe, the late Rebbe's son-in-law, Rabbi Menachem Mendel Schneerson, delivered a Chassidic discourse (maamar) entitled Basi LeGani ("I Came into My Garden"), signifying his formal acceptance of the leadership of the Chabad-Lubavitch movement.
Links:
Yud Shevat: A Day of Two Rebbes
Learn Basi LeGani
Biography of Rabbi Yosef Yitzchok
Biography of Rabbi Menachem Mendel
Yahrzeit Observances (The Rebbe's Letter)
Chabad Chassidim observe the customs of the yahrtzeit (anniversary of the passing) of the sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneersohn (1880-1950), as established by his son-in-law, Rabbi Menachem Mendel Schneerson (1902-1994), who succeeded him as Rebbe following his passing on the 10th of Shevat in 1950.
Naturally, we think of the Jewish people as a conglomerate of many Jews. But the Baal Shem Tov saw the Jewish people as a single, indivisible whole.
Think of a geometrical point. A point is indivisible, but not because it is too hard, too big, or too small to cut up. A point simply has no area to be divided. That’s what makes it a point.
And yet, from a point you can extend infinite lines radiating in infinite dimensions.
In a somewhat similar way, but far beyond, all Jews are one Jew. Which means that in any one Jew, you will find all of us—just from a different angle.
So that whatever happens to any one of us instantaneously happens to the entire Jewish people. Not by some ripple effect or resonance. But because any one sample of the whole is the whole and the whole is one.
And so, the Baal Shem Tov taught, when the light of any one Jewish soul breaks free, the entire nation is redeemed along with it.
And accordingly, the Rebbe wrote, the ultimate exodus of our entire people is also a personal, intimate liberation for every Jew.