Today, on the 5th of Av, is the Yahrtzeit of Rabbi Yitzchak Luria Ashkenazi, the Arizal (1534-72).

The Ari Hakadosh revolutionized Kabbala study & is regarded as one of the most important mekubalim in history.

Mechaber of Eitz Chaim, Sha’ar Hakavanos etc.