In my essays on Symbolism & Structure, I often refer to The Story of Heathcliff.1
While Wuthering Heights is a narrative of two families, it is the existence of Heathcliff which gives birth to the story. A story woven through three generations…
Heathcliff is a foundling…
“Starving, and houseless, and as good as dumb,” Heathcliff was discovered as an approximately seven-year-old child, on the streets of Liverpool.
Heathcliff is an Earnshaw by nature, though not by blood, and his virtues are the Earnshaw virtues: steadfastness, determination, and an unswerving dedication to the objects of his devotion.2

While we meet adult Heathcliff on the first page of Volume I: Chapter I, we learn the story of how he came to Wuthering Heights from Ellen “Nelly” Dean. In Chapter IV she remembers the day Heathcliff tumbled out of the master’s great coat:
The master tried to explain the matter; but he was really half dead with fatigue, and all that I could make out, amongst [Mrs. Earnshaw’s] scolding, was a tale of his seeing it starving, and houseless, and as good as dumb in the streets of Liverpool, where he picked it up and inquired for its owner. Not a soul knew to whom it belonged, he said, and his money and time being both limited, he thought it better to take it home with him at once, than run into vain expenses there; because he was determined he would not leave it as he found it.3
Mrs. Earnshaw was livid. Fourteen-year-old Hindley and six-year-old Catherine were in awe. Why a man with two children at home felt compelled to scoop another child up off the streets of Liverpool and boldly relocate him, we don’t know?
However, we will learn the consequence of his hasty decision.
As housekeeper Mrs. Dean details for tenant Lockwood (and for us) the child’s impact on the family. She explains that what appeared to them a, ‘dirty, ragged, black-haired boy,’ was within days, christened Heathcliff—‘it was the name of a son who died in childhood, and it has served him ever since, both for Christian and surname.’
Also, within those few days, “Miss Cathy and he [became] very thick; but Hindley hated him.” Mrs. Dean confesses: “To say the truth I did the same…”
He seemed a sullen, patient child, hardened, perhaps, to ill-treatment: he would stand Hindley’s blows without winking or shedding a tear, and my pinches moved him only to draw in a breath, and open his eyes as if he had hurt himself by accident, and nobody was to blame.
And so, young Heathcliff was snatched from Liverpool and raised far from society in a home where he garnered brief affection from the elder Earnshaw, was mildly tolerated by Mrs. Earnshaw, physically and psychologically abused by Hindley Earnshaw as well as the housekeeper’s daughter (Nelly Dean)…and, Catherine? Catherine was different.
Cathy was much too fond of Heathcliff. And that is where the real story begins…
Heathcliff is the focus of most of my essays; unless they are part of the Read With Me series, those essays likely contain spoilers.
Brontë, Emily. The Annotated Wuthering Heights. Edited by Janet Gezari, The Belknap Press of Harvard University Press, 2014.
While charitable, in most aspects, Earnshaw shows few signs of altruistic behavior. Brontë was well aware of orphaned and starving children (fleeing the famine in Ireland), and likely, Heathcliff is modeled after those children.