In the novel The Rose and the Yew Tree, Rupert St. Loo (Lord St. Loo) is a cousin of Isabella Charteris. The pair is expected to marry, when he returns from the war. He is described as being tall and handsome, resembling a young god.
Rupert St. Loo is the nephew of Adelaide St. Loo.
Rupert's mother is from New Zealand, and after she became widowed moved back there with her son.