Modernism (1919-19?)
Modernism was a reaction to Victorianism and Realism and the bourgeois moral and literary norms they espoused. It was also a horrified reflex to the mass slaughter of World War I.
It was both a philosophical and psychological attitude as well as a literary agenda.  As a literary agenda, it:
Emphasized form and style over content,
Espoused objectivity,
Employed ambivalence, irony, and paradox,
Appropriated and invented mythic structures,
Used allusive, sometimes multi-lingual verbal strategies,
Developed reflexive, confessional, and overly self-conscious characters,
Dispensed with the narrator/guide.