Reich (n.)

German, "kingdom, realm, state," from Old High German rihhi "realm," from Proto-Germanic *rikja "rule" (source also of Old Norse riki, Danish rige, Old Frisian and Middle Dutch rike, Dutch rijk, Old English rice, Gothic reiki), from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule." Don Ringe, "From Proto-Indo-European to Proto-Germanic" [Oxford 2006] identifies it as a Celtic loan-word in Germanic rather than a direct evolution from PIE, based on the vowel. Used in English from 1871-1945 to refer to "the German state, Germany." Most notoriously in Third Reich (see third); there never was a First or Second in English usage.