L. le Bourgeois

Loys “Louis” Bourgeois was a French composer and music theorist of the Renaissance. He is most famous as one of the main compilers of Calvinist hymn tunes in the middle of the 16th century. One of the most famous melodies in all of Christendom, the tune known as the Old 100th, to which the Protestant doxology is often sung, is commonly attributed to him.

Adapted from the Wikipedia article on Louis Bourgeois (composer).