Rare footage posted online Sunday appears to show one of European Jewry's greatest Torah scholars, Rabbi Yisrael Meir Kagan - more popularly known as the Chafetz Chaim - attending the First World Congress of the World Agudath Israel in Vienna.

The 10-day Congress took place in 1923, making the video nearly 100 years old.

An elderly Chafetz Chaim can be seen arriving at roughly 57 seconds in, alongside other leading Ashkenazic rabbis and community heads of his generation.

The Chafetz Chaim was perhaps the most important codifier of contemporary halakha (Jewish law) in the Ashkenazic world, and his magnum opus - the Mishne Berura - is still used today by many as a basis for halakhic rulings.

"Chafetz Chaim" was in fact the name of another of his more famous works, a masterpiece of Jewish ethics concerning the Torah's laws of speech that is widely read throughout the Jewish world.