WARNING: MANY SPOILERS AHEAD. READ AT YOUR OWN RISK.
Henry York is the seventh son of Hyacinth and Mordecai Westmore, born in Hylfing. As a baby, he was pushed through the cupboard located at Badon Hill and ended up in Kansas, in the house of Dorothy Willis' father. His uncle Frank Willis and aunt Dorothy wanted to adopt him as one of their own, but Dorothy's sister, Ursula, and her husband, Phil, beat them to it and took Henry to their home in Boston.
There Henry lived for about 11 years of his life until his adopted parents were kidnapped on a bike tour and held for ransom. Henry was then sent to live with his uncle and aunt in Henry, Kansas. He found 100 cupboards on the wall of his bedroom and explored them with the help of his 12-year-old cousin, Henrietta. This eventually leads to the finding of two characters; Eli of the FitzFaeren and Richard, a sickly boy who follows Henry back through the cupboards and currently lives with the Willis family. Henrietta accidentally awakens the witch, Nimiane, who bites Henry and tastes his blood, after which she begins to regain her powers. Nimiane later escapes the cupboards and attacks Henry and his family. They manage to defeat her, but small droplets of her blood splash onto Henry's cheek, creating an accidental bond between the two.
In the second book, Dandelion Fire, Henry (who is a pauper son, the seventh son of a seventh son)'s powers awaken, and he experiences the usual period of blindness that comes between the awakening of powers and the full transformation into a Green Man. But Henry has no one to guide him through these times, and he is rushed to a hospital, where he is soon released on the supposed conclusion that he was almost struck with lightning and is simply imagining himself blind. Later on, Henry is captured by the powerful wizard Darius, who wishes to stop his powers from growing and connect them to Darius' own powers. Henry escapes and finds safety at the home of Ron and Nella. Later on in the book, Henry is reunited with his mother, Hyacinth, and father, Mordecai, who had been trapped inside a faren hill for good many years and was freed by Henry.
He went on to live a double life: one in the city of Hylfing, where his uncle Frank became the mayor and lived there with his family, and one as a top-notch baseball player in Kansas.
Adoptive Mom: Ursula
Adoptive Dad: Phil
Aunt: Dorothy Willis
Uncle: Frank Willis
Cousins: Penelope Willis
Biological mom: Hyacinth
Biological Dad: Mordecai
Grandfather: Amram Iothric
Brother: James (and more that weren't mentioned)