Elizabeth & Lily — Hilary Bailey

Spanning 30 years from 1886 to 1917, this novel, first published in 1997, follows the lives of two women from different ends of the social scale. They are reunited as adults and find that their friendship helps them through the bitterness and cruelty of war, and the legacies of their own childhoods.

Somewhere between Sarah's Water's The Night Watch and William Boyd's Any Human Heart, friendship transcends class divides and the cruelty of war.