Elijah ben Shlomo Zalman Kremer, (Hebrew: ר' אליהו בן שלמה זלמן) known as the Vilna Gaon or Elijah of Vilna, or by his Hebrew acronym Gra ("Gaon Rabbenu Eliyahu") or Elijah Ben Solomon, (Vilnius April 23, 1720 – Vilnius October 9, 1797), was a Talmudist, halachist, kabbalist, and the foremost leader of non-hasidic Jewry of the past few centuries. He is commonly referred to in Hebrew as ha-Gaon ha-Chasid mi-Vilna, "the saintly genius from Vilnius."
He was one of the most influential rabbinic authorities since the Middle Ages, and—although he is counted among the sages known as the Acharonim—he is held by many authorities after him as belonging to the Rishonim (Rabbinic authorities of the Middle Ages). Large groups of people, including many yeshivas, uphold the set of Jewish customs and rites (minhag), the "minhag ha-Gra," which is named for him, and which is also considered by many to be the prevailing Ashkenazi minhag in Jerusalem.
Born in Vilnius, capital city of Grand Duchy of Lithuania, the Gaon displayed extraordinary talent while still a child. By the time he was twenty years old, rabbis were submitting their most difficult halakhic problems to him for legal rulings. He was a prolific author, writing such works as glosses on the Babylonian Talmud and Shulchan Aruch known as Bi'urei ha-Gra ("Elaboration by the Gra"), a running commentary on the Mishnah (Shenoth Eliyahu ("The Years of Elijah"), and insights on the Pentateuch entitled Adereth Eliyahu ("The Splendor of Elijah"). Various Kabbalistic works have commentaries in his name, and commentaries on the Proverbs and other books of the Tanakh were written later on in his life. None of his manuscripts were published in his lifetime, and he was perhaps too humble or shy to give them to anyone other than his family.
When Hasidic Judaism became influential in his native town, the Vilna Gaon joined the "opposers" or Mitnagdim, rabbis and heads of the Polish communities, to curb Hasidic influence. In 1777 one of the first excommunications against the nascent Hasidic movement was launched in Vilna.
As the Mishna in Tractate Peah (1:1) states: "The study of Torah is equal to all of the mitzvos", the Gaon encouraged his chief pupil, Rabbi Chaim Volozhin, to found a yeshiva (rabbinic academy) in which rabbinic literature should be taught. The yeshiva was opened at Volozhin in 1803, some years after the Gaon's death, and revolutionized Torah study, with resulting impact on all of Orthodox Jewry. He encouraged his students to study secular sciences, and even translated geometry books to Yiddish and Hebrew, chief among them Sefer HaEuclid.
An example of the Gaon's genius can be seen in his commentary on Genesis in his text "Aderes Eliahu", published by his son. The medieval Spanish Jewish community leader Ramban asks (though the Gaon never mentions Ramban's question, his grandson made the connection to the Ramban's question in his commentary on his grandfather's commentary) "Is light the absence of darkness as Thomas Aquinas and others derived from the Prophets?". The commentary in Aderes Eliahu is on verse 1:4 of Genesis.
And God divided the light from the darkness "I must infer from the verse that darkness is a separate creation from light and unrelated, rather than the physical absence of light"... "is different from 'the darkness' mentioned in the first verse."
Read more about Vilna Gaon: Youth and Education, Methods of Study, Antagonism To Hasidism, Other Work, Asceticism, Works, Influence, Death