From"California Place Names", E G Gudde, U of CA Press, 1949:
"German......Artois [Glenn] was formerly called Germantown."
"Artois [Glenn]. The place was settled about 1876 and called Germantown. In 1918 the old American name was replaced by the French Artois, after the district on the Western Front in World War I"
Additional info on use of "German" in names. In many cases, the nickname Dutch (for Duetch) is used in place of German in California toponymy and topo features with German in their name may not have been named for German settlers; German was a relatively common family name in Spanish California.