[4] Charles was born in Trent Vale on 29 March 1848, to a Galway Irish family which had settled in the industrial Midlands borough of Stoke-on-Trent.

Keary then became fascinated by Scandinavian history and primitive mythology, then a promising new academic field, and wrote a number of scholarly books on such topics: The Vikings in Western Christendom (1890) stood as a standard work for many decades.

These works were unusual, using a lack of conventional structure in an attempt to suggest the chaos of reality, allied to close observation and a dispassionate approach to character.

Keary tried the then-fashionable form of verse drama, with The Brothers: a Fairy Masque (1902) and Rigel: a Mystery (1904), and moved with more success into philosophy with The Pursuit of Reason (Cambridge University Press, 1910).

"[11] Keary wrote the libretto for the opera Koanga (1904) by the composer Frederick Delius, with whom he had detailed discussions, but the collaboration was short and fraught, and led to no further work between them.