John Langdon Haydon Down (18 November 1828 – 7 October 1896) was a British physician best known for his description of the genetic condition now known as Down's or Down syndrome, which he originally classified in 1862.

[2] His father was descended from an Irish family, his great-great grandfather having been the Protestant Bishop of Derry and Raphoe.

[4] At the age of 18, he went to London where he got a post working for a surgeon in the Whitechapel Road where he had to bleed patients, extract teeth, wash bottles and dispense drugs.

[5] There he had a career distinguished by honours and gold medals and he qualified in 1856 at the Apothecaries Hall and the Royal College of Surgeons.

He and his wife Mary transformed Earlswood from a place of horror where patients were subject to corporal punishment and kept in dirty conditions and unschooled, to a happy place where all punishment was forbidden and replaced with kindness and rewards, the patients' dignity was valued and they were taught horse riding, gardening, crafts and elocution.

[4] Down restructured the administration of the Asylum and started a regimen of stimulation, good food, and occupational training.

Down used this reasoning to argue against a tendency he perceived in his day to regard different races as separate species.

Down eventually retired from Earlswood in 1868 after the lords refused to give him the money he needed to display the artwork of some of his patients at an exhibition.

[4] After resigning from Earlswood, Down set up his own private home for those with developmental and intellectual disabilities at Normansfield, between Hampton Wick and Teddington.

The home's first occupants were 18 mentally disabled children of upper-class members of the community such as lords and physicians.

In the home, Down and his wife did their best to educate the children and exposed them to a wide variety of mentally stimulating activities.

[4] Down also made contributions to medicine through his research and was the first person to publish a description of the Prader-Willi syndrome, which he called 'polysarcia'.