R. Judah Ashlag (1886–1954) was an Israeli kabbalist and rabbi. Ashlag, the most important 20th century kabbalist, who was born in Warsaw, was educated in ḥasidic schools. He was a disciple of Shalom Rabinowicz of Kalushin, and of his son Yehoshah Asher of Porissov. He also had a teacher of Kabbalah whose name, he maintained, he was not allowed to divulge. Ashlag immigrated to Palestine in 1920 and settled in the Old City of Jerusalem, where he established a yeshivah, named Bet Ulpena le-Rabbanim, and instructed his pupils in halakhah and Kabbalah. Between 1926 and 1928 he resided in London, where he wrote his first kabbalistic works, Panim Me'irot and Panim Masbirot (1927–30), a double commentary to the Eẓ Ḥayyim by R. Ḥayyim Vital . In 1946 he moved to Tel Aviv. Ashlag wrote extensive commentaries to the Lurianic corpus and the Zohar. His writings include Or Pashut, a commentary to the Lurianic compilation Beit Sha'ar Ha-Kavanot (1941); Talmud Eser Sefirot (1955–67), on the kabbalistic doctrines of R. Isaac Luria ; Ha-Sullam ("The Ladder," 1945–60), a commentary on the entire Zohar and Zohar Ḥadash (completed by his brother-in-law R. Yehuda Ẓevi Brandwein ).. Other writings of Ashlag, letters to his disciples, commentaries, and homilies, were published posthumously in four volumes entitled Peri Ḥakham (1985–2003). Ashlag, who adopted socialist and communist ideas and integrated them in his kabbalistic systems, led discussions with various leaders of Israel's Labor Party, including Israel's first prime minister, David Ben-Gurion. In his extensive writings, Ashlag presents a highly complex and innovative kabbalistic doctrine. The central notion of his new kabbalistic system is that the Creator, who is defined as the infinite "will to bestow," created through a complex and dialectical process of emanation a "will to receive" the benefits bestowed by Him. Human beings stand at the end of the emanation process as a pure egoistic will to receive. Yet, recognizing their situation, human beings are able to change their nature, and try to transform their egoistic "will to receive" into a quasi-divine "will to bestow." As such a transformation is achieved, the gap between human and divine nature diminishes and man achieves spiritual perfection. This process also has a social feature, as the road to spiritual perfection is also the road to establishing a perfect, communist community in which every individual contributes according to his ability and receives according to his needs. Ashlag believed that Kabbalah should not be kept esoteric and attempted to disperse Kabbalah to the larger public through his popular treatises and his Zohar translation. After Ashlag's death, his kabbalistic doctrines were taught by his sons, R. Barukh Shalom and R. Shelomo Benjamin, and by his disciples, R. Levi Krakovsky and R. Yehuda Ẓevi Brandwein . Various contemporary kabbalistic movements, including the Kabbalah Center headed by R. Philip Berg and Bnei Baruch headed by R. Michael Leitman are based on the kabbalistic system of Yehudah Ashlag.