By order of King James I of Aragon (Spain), Nachmanides (Rabbi Moses ben Nachman, 1194-1270) was compelled to participate in a public debate, held in the king's presence, against the Jewish convert to Christianity, Pablo Christiani. His brilliant defense of Judaism and refutations of Christianity's claims served as the basis of many such future disputations through the generations.
Because his victory was an insult to the king's religion, Nachmanides was forced to flee Spain. He came to Jerusalem, where he found just a handful of Jewish families living in abject poverty, and revived the Jewish community there. The synagogue he built in the Old City is in use today, and is perhaps the oldest standing synagogue in the world.
On this date in 1940, the building at 770 Eastern Parkway in the Crown Heights section of Brooklyn, New York was purchased by Agudas Chassidei Chabad (the Chabad-Lubavitch community) to house the living quarters, study and office, Yeshivah, and synagogue of the sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneersohn (1880-1950), who had arrived in New York (following his rescue from Nazi-occupied Warsaw) five months earlier. It also served as the headquarters of his son-in-law and successor, the Rebbe, Rabbi Menachem M. Schneerson, and continues to be the center of Chabad-Lubavitch's global network of institutions of Jewish education and outreach.
From a letter of the previous rebbe to a chief rabbi:
Fighting evil is a very noble job. But it is not your mission in life.
Your job is to bring in more light.
Stay completely out of such battles, arguments, and debates.
Not because you aren't able to win. Not because your heart is too delicate to go to war.
But because every bit of your energy needs to be dedicated exclusively to strengthening the good that you have built, to give your very life for it.
Then, only then, can you succeed.