Rabbeinu Meir Shaliach-Tzibbur lived in Germany in the early to mid-11th century and was born probably around the year 4780 (1020). He was a renowned Talmudist and liturgist i.e. composer of Piyutim. He was the Shaliach Tzibbur in the city of Worms, hence is unusual name. Rashi quotes him often and just this week whilst learning נ"ך with my study partner we came across a Rashi in Hosea that quoted a commentary from him. He composed a total of 49 Piyutim, 40 of them in Hebrew and the remainder in Aramaic. However, only about 15 are still known to us today. His most awe-inspiring Piyut that has come down to us is Akdamus, customarily recited by Ashkenazi communities worldwide on the Yom Tov of Shavuot. This Piyut is a beautiful praise of Hashem, His Torah and His People and was written in Aramaic. He had a son called Rabbeinu Yitzchak who was killed sanctifying G-d’s name in the city of Worms, probably during the First Crusade.
There is a tradition that his Piyutim were so beautiful and inspiring that even the Angels on high would sing before Hashem in their own name. Rashi in his Teshuvot (Responsa) writes about him ‘’and when I arrived from there and I heard from that great Tzaddik Reb Meir ben Reb Yitzchak that he arranged it that way, I also enacted that we should act this way in my residence/town’’ loosely translated.
He was Niftar in the year 4850 (1090).
Source: Artscroll: The Early Rishonim, 2006 and the Sefer שמות חכמים by Rabbi Avraham Meir Weiss, 5769 (2009).