Lunel was born in Aix-en-Provence, France, to a family that belonged to a Jewish subculture that had roots in the area for at least five centuries.

After growing up in the region, Lunel taught law and philosophy in Monaco.

Though often referred to as the last known speaker of Judeo-Provençal, he did not actually speak it; at most, he learned a few words and sentences from his great-grandparents.

[1] He was a childhood friend of the composer Darius Milhaud, and wrote the librettos of Milhaud's operas Esther de Carpentras ("Esther of Carpentras," 1938, based on Judeo-Provençal folklore), Les malheurs d'Orphée ("The Misfortunes of Orpheus," 1924), and David (1954).

He also provided the libretto for Henri Sauguet's La chartreuse de Parme, premiered in 1939.