Although precise periodization varies somewhat, the "modern" period in English literature generally falls between the two world wars, World War I and World War II. There were both "modernist" and "anti-modernist" writers during this period, with many of the major war poets and "Georgians" falling into the "anti-modernist" camp.
Modernism as a movement was international, urban, technically experimental, trans-generic, and strongly anti-popular, developing to a great degree directly from the anti-bourgeois strain in symbolism, the movement from which it descended.
In the novel, one finds a dramatic bifurcation between plot-dominated "popular" writing -- mystery and science fiction were two major popular genres developing in the period -- and the literary novel, that often was concerned with the interior consciousness of one or more protagonists (in the case of Woolf or Joyce). Unreliable or intrusive narrators were common features of the literary fiction of the period.
Often modernism viewed itself as having a quasi-religious mission (similar to Romanticism), as when Stephen Daedalus, at the end of James Joyce's Portrait of the Artist as a Young Man says:
"Welcome, O life! I go to encounter for the millionth time the reality of experience and to forge in the smithy of my soul the uncreated conscience of my race."