Mary Shelley had lived for a year after her husband's death with Leigh Hunt and his family in Genoa, where she often saw Byron and transcribed his poems.

She had resolved to live by her pen and for her son, but her financial situation was precarious.

Her name appears on the second edition of Frankenstein, published in France in 1823.

On July 23 of that year, she had left Genoa for England and stayed with her father and stepmother in the Strand until a small advance from her father-in-law enabled her to lodge nearby.

Sir Timothy Shelley had at first agreed to support his grandson, Percy Florence, only if he were handed over to an appointed guardian.

Mary had rejected this idea instantly, and managed instead to wring out of Sir Timothy a limited annual allowance (which she has to repay when Percy Florence inherits the estate), but to the end of his days he will refuse to meet her in person and deal with her only through lawyers.

Mary has busied herself with editing her husband's poems, among other literary endeavors, but concern for her son restricts her options.

Sir Timothy has threatened to stop the allowance if any biography of the poet were published.

In 1826, Percy Florence becomes the legal heir of the Shelley estate after the death of Charles Shelley, his father's son by Harriet Shelley.

Sir Timothy raises Mary's allowance from £100 a year to £250 but remains as difficult as ever.

Mary enjoys the stimulating society of William Godwin's circle, but poverty prevents her from socializing as she wishes.

She also feels ostracized by those who, like Sir Timothy, still disapprove of her relationship with Percy Bysshe Shelley.

In the summer of 1824, Mary had moved to Kentish Town in north London to be near Jane Williams.

Jane later disillusioned her by gossiping that Percy had preferred her to Mary, owing to Mary's inadequacy as a wife.

At around this time, Mary is working on her apocalyptic science fiction novel, The Last Man; and she assists a series of friends who are writing memoirs of Byron and Percy Shelley—the beginnings of her attempts to immortalize her husband.

She also meets the American actor John Howard Payne and the American writer Washington Irving, who intrigues her.

Payne falls in love with her and in 1826 asks her to marry him.

She refuses, saying that after being married to one genius, she could only marry another.

Payne accepts the rejection and tries without success to talk his friend Irving into proposing himself.

Mary is aware of Payne's plan, but how seriously she takes it is unclear.

The Last Man, published in February 1826, tells of a future world that has been ravaged by a plague.

The novel is harshly reviewed at the time, and will remain virtually unknown until a scholarly revival beginning in the 1960s.

It is notable in part for its semi-biographical portraits of Romantic figures in Shelley's circle, particularly her late husband and Lord Byron.