From 1905 to 1910 he studied classical, German and Romance philology at the University of Berlin, where his teachers included Eduard Norden, Gustav Roethe, Erich Schmidt and Adolf Tobler.
[4][3] He served as the dean of the Faculty of Philosophy at Frankfurt for a year from 1932 to November 1933, and oversaw the implementation of the 7 April 1933 Law for the Restoration of the Professional Civil Service, which resulted in the dismissal of Max Horkheimer, among others.
[2] During the Nazi period (1933–1945) he published less and while he continued to work on his multi-volume dictionary, he suspended his early interests in Geistesgeschichte and Völkerpsychologie, leaving out the antisemitic tropes in Gautier de Coincy from his 1938 article on the medieval author.
[6] Having referred to Nazism in wartime as a "temporary storm", in his early post-war writings Lommatzsch described the World War II's outcome as a "collapse" and its aftermath as "days of darkness".
From 1925 he published the Altfranzösisches Wörterbuch, an Old French dictionary based on a massive collection of notes compiled by Adolf Tobler.