A hexalogy (from Greek ἑξα- hexa-, "six" and -λογία -logia, "discourse") is a compound literary or narrative work that is made up of six distinct works.
The word apparently first appeared in English as a borrowing from German, in discussions of August Bungert's Wagnerian opera cycle entitled Homerische Welt based on the Iliad and the Odyssey.
[1] (He planned two tetralogies, but the third and fourth operas of the eight were never written.)
Both pentalogie and hexalogie were used by Théophile Gautier in 1859.
[2] In 1923 the word was applied by an American reviewer to Johannes V. Jensen's The Long Journey.