At the time, he was a successful illustrator and painter based in England. Today he might be better known as being the father of Terence Cuneo, a beloved and honored British illustrator.
But he wasn't British by origin. Cyrus (or "Ciro" as he was called) was born in San Francisco to Italian immigrants, growing up in the North Beach part of town. He became a boxer to help support himself while studying art in Paris where he greatly impressed James McNeill Whistler, one of his teachers. A biographical note is here, and a PDF with useful information is here.
Cuneo was versatile, as can be seen in the collection below.
Illustration from a book of A.J. Raffles stories by E.W. Hornung
Canadian trapper attacked by wolves
Cuneo spent some time in Canada, mostly doing artwork for Canadian Pacific. This illustration might be for a fiction piece.
Frontispiece for "The Air Patrol" by Herbert Strang (pseudonym)
The Sinking of the Gneisenau
This looks like an Illustrated London News sort of illustration. The Gneisenau was a German cruiser, part of Admiral von Spee's fleet that was mostly destroyed by the British in the Battle of the Falklands, 8 December 1914.
Japanese Tea Garden
Now for a change of pace from book and magazine illustration ...
The Picnic
Nell Marion Tenison - the artist's wife
The Diners - 1913
Arriving at the Ball