While Lord John Grey escorts Percy Wainwright to visit Minerva Grey for dance lessons, he mentions that a dance instructor is in the employ of the family for his nephews; Benjamin, Adam, and Henry. Henry was present at his grandmother Benedicta's wedding to his new grandfather Sir George Stanley - the same day his new cousin Cromwell Stubbs is born. Henry, along side his brothers, attend the christening of their new baby sister Dorothea Grey at St James church. Famished following the christening he and his brothers demand something to eat from their father, being joined by their uncle.
Henry and his brothers are mentioned in a letter from Harold Grey that Lord John Grey receives while he is in Canada. Hal conveys his sons' firm belief that no "Red Indian" would succeed in taking his scalp, and recommends bringing home three "tommyhawks" for the boys.
Unbeknownst to Henry, his uncle John was casually observing from the house as he and his older brothers Benjamin and Adam played a game of tigers and hunters. His toddler sister Dottie was occupied with the nurse at the goldfish pond, the nurse giving a mere eye roll to his and his brother's antics as they cursed during their game. Despite his mother's insistence that his father and uncle not curse in English around them, they still picked up the words. Following John's duel with Edward Twelvetrees, Henry and his brothers descend upon him while he is recovering at Argus House. All three want to see their uncle's injuries and hear the gory details about the duel from John himself. They bestow awed admiration on the impressive wound, a six inch gash across the left side of their uncle's upper chest. They ask if it hurts, and John replies that his leg wound is a greater source of discomfort. They are instantly eager to see it, and in their rush they nearly pitch him off his bed. Adam makes an observation about their uncle's private area and the brothers all giggle at their uncle's reply. Over shared milk and bread, the three brothers update their uncle on the happenings of the house: Nasonby injured his ankle, Cook had a disagreement with the fishmonger, their spaniel Lucy had her puppies, and Mrs. Weston had a fit. As Adam and Henry snuggle next to their uncle, John requests that Ben provide entertainment. Benjamin's rendition of "The Twelve Days of Christmas" is interrupted by the arrival of their mother, who hurries them out of the room.
In late 1776, Henry is wounded in America and captured. He can't eat, as there are bits of metal in his abdomen that surgeons have been unable to extract. Local prison officer is worried that a potentially lucrative prisoner might die, and moves Henry to the house of Mercy Woodcock, a young African woman whose husband is a rebel fighting for the Continental army. Mrs. Woodcock nurses Henry and a bond between them develops. In June 1777, Henry's uncle Lord John Grey and his sister Dottie arrive in Philadelphia. Grey visits Henry and, noticing the feeling between him and Mrs. Woodcock, is worried that should she become a widow, Henry might want to marry her, which would cause a family scandal. Henry's condition is still serious and he says he would rather die than have another surgery, but Grey is determined to find another doctor who might be able to help him. In late November 1777, William tells Grey that he knows an excellent surgeon who might be able to help Henry. He then goes to Valley Forge under a flag of truce to fetch Dr. Denzell Hunter and his sister Rachel. At Christmas, Denzell performs a surgery on Henry, but is only able to remove one piece of metal from his body. In April 1778, Claire Fraser anaesthetizes Henry with ether and performs the final surgery on him, with Denzell assisting her.
Like his siblings, Henry is stubborn and determined.
Henry takes after his mother rather than Hal, being normally ruddy-cheeked and of a rather stocky build.
- Mercy Woodcock: As of 1778, Henry was having an affair with Mrs. Woodcock, a married woman whose husband may or may not have died after the siege of Fort Ticonderoga.
- Henry is from the Germanic name Heimirich which meant "home ruler", composed of the elements heim "home" and ric "power, ruler".
- Grey has two possible origins: 1) an Anglo-Saxon, Old English nickname for someone with grey hair or a grey beard, derived from the Old English pre 7th Century word "graeg", grey; 2) from the place called "Graye" in Calvados, Normandy, so called from the Old Gallo-Roman personal name "Gratus" meaning "Welcome" or "Pleasing", with the suffix "acum" meaning settlement or village.
- Age as of the end of Written in My Own Heart's Blood.
- Probable error; as the youngest son of a duke, Henry would not use one of his father's lesser titles. Only the heir apparent (i.e. Benjamin, and even Benjamin's son, Trevor) could use a lesser title as a courtesy.
- Courtesy title only; appropriate to the younger son of a duke.
- Behind the Name: Henry - accessed 03 June 2016
- The Internet Surname Database – accessed 19 June 2014