While everyone else is out burning down the town with their bonfires to celebrate the yarzheit of Rabbi Shimon Bar Yochai (who probably didn’t die on Lag B’Omer anyway), I wanted to take the opportunity to remember someone who actually did die on this day, and was almost as influential (certainly for Ashkenazi Jews) as the RaSHBI.
Lag B’Omer is the day that the Rema passed away, in Cracow in 1572. He was 52 years old. Rema (or Rama) is an acronym for his real name ‘Rabbi Moshe Isserles’.
He is most famous for his commentary on the Shulchan Aruch (known as the Mapa – the tablecloth) which not only included Ashkenazi customs within R’ Yosef Caro’s code of law, but more importantly ensured that there would be only one standard text of Halacha for all of Jewry, rather than separate books for Ashkenazim and Sefardim. According to tradition he had written a work similar to the Shulchan Aruch, but destroyed it upon finding out that R’ Caro had already written his book.

Here is what Wikipedia has to say about him:

Rabbi Isserles was born in Cracow. His father, Israel Isserles, was a prominent Talmudist, said to have been independently wealthy, and probably headed the community; his grandfather, Jehiel Luria, was the first Rabbi of Brisk. Isserles studied in Lublin under Rabbi Shalom Shachna, who became his father-in-law. Among his fellow pupils were his relative Solomon Luria (Maharshal), and Chayyim b. Bezalel, an older brother of the Maharal. Rema’s wife died young, at the age of 20 and he later established the “Rema Synagogue” in Cracow in her memory (originally his house, built by his father in his honor—which he gave to the community). He later married the sister of Joseph ben Mordechai Gershon Ha-Kohen.
He returned to Cracow about 1550, when he established a large yeshiva and, being a wealthy man, supported his pupils at his own cost. In his teaching, he was opposed to pilpul and he emphasized simple interpretation of the Talmud. In 1553 he was appointed as dayan; he also served on the Council of the Four Lands. He became a world-renowned scholar and was approached by many other well-known rabbis, including Yosef Karo, for Halachic decisions. He was one of the greatest Jewish scholars of Poland, and was the primary halakhic authority for European Jewry of his day. He died in Cracow and was buried next to his synagogue. On his tombstone is inscribed: “From Moses (Maimonides) to Moses (Isserles) there was none like Moses”. Until the Second World War, thousands of pilgrims visited his grave annually on Lag Ba’omer, his Yahrzeit (date of death).

In addition to the mappa (and the destroyed Shulchan Aruch) he wrote the Darchei Moshe, which is a commentary on the Tur, as well as Torat HaChatat (a Halachic sefer mainly on kashrut), Torat HaOlah (philosophy and hashkafa) and a collection of responsa.

This is the archway above the Shul built by the Rema.

So, once you have recovered from your bonfires and study of the Zohar, perhaps you could open up the Shulchan Aruch, learn some Halacha and bring merit to the soul of the Rema.

May his Soul Be Bound in the Bonds of Eternal Life