Doctor Thorne remains indisputably one of Trollope's greatest achievements. Paradoxically, it was not a favourite with its author, but then, as so often, he was a poor judge of his own work. Interestingly, the plot was devised not by the author but by his brother Tom with whom he was staying in Florence when, as he confessed, 'I was cudgelling my brain for a plot'.
Frank Gresham is heir to Greshamsbury Court, once a very rich estate but now much depleted, mortgages on the estate being held by the self-made millionaire Sir Roger Scatcherd. Frank is consequently under a great deal of pressure to marry money; particular pressure is applied by his mother, the snobbish sister of the Earl de Courcy, but Frank is in love with Mary Thorne, niece of the eponymous Doctor with whom she lives. However, it is known only to Doctor Thorne that Mary is in fact Sir Roger's eldest neice, albeit illegitimate: Sir Roger, a stone-cutter who has made his fortune through ruthless business dealings and has been ennobled because of his success, is paradoxically a drunkard and an ex-convict, a result of killing his sister's seducer, Mary Thorne's father, many years before. Sir Roger is unaware of Mary's true identity, or even that she survived.
In this, the third Barchester novel there are very few clerics - Mrs Proudie, for example, having what amounts to a cameo appearance - and this is chiefly because the author found himself more concerned with the county families. The happy result is the widening of the series' scope in unexpected directions, most notable in the portrayal of Frank's selfish mother Lady Arabella Gresham, the slightly enigmatic figure of Dr Thorne, and particularly the depiction of Mary Thorne herself, Trollope's heroine.
