Daniel was born in Russia. In his seventh year, his mother became nostalgic for her home and brought Daniel to Yorkshire. He meets Cecilia in the coastal town of Scarborough and the two become inseparable. Daniel begins attending boarding school in southern England and spends every summer in Yorkshire with his mother, where he can be with his beloved Cecilia, whom he knows he is destined to marry one day.
Daniel has a complex relationship with Cecilia's father, Nathaniel Ley. Nathaniel loves Daniel and calls him his son, but is jealous of Cecilia's adoration of him, and how her plans for early marriage will impact his vision for her gift. Despite their disagreement on the age Cecilia can marry, Daniel and Nathaniel have a bond that defies description, and spend many hours playing chess, fencing and riding. Daniel has a wonderful relationship with Cecilia's mother, Anne Ley, and her younger brothers, Adam and Miles.
Daniel has a very close karmic relationship with Ambrose de Ripariis, Nathaniel's partner and the godfather to the three Ley children. Over time Daniel realizes that he and Ambrose are spirit twins.
Daniel plans to become a physicist upon his graduation from Cambridge. His favorite form of relaxation other than chess and fencing is riding his beloved steed, Ballista, and being with his Siberian Husky, Dmitri.
Daniel is sensitive, poetic, passionate, and highly intelligent, but he has demons that no one can explain and becomes inexplicably violent when provoked. Cecilia and Ambrose are the only people who can calm his demons.
His nemesis is George Peacock. The Graysons and Leys have been feuding with the Peacock family for centuries.
Following the tragic death of Cecilia in the summer of 1899, Daniel began destroying himself, and would reject any help his loved ones would offer. He starts heavily drinking, and getting into more and more fights. During that time, he has an extremely intense confrontation with Nathaniel Ley.
Ambrose tries to snap Daniel out of his self-destruction, but Daniel tells him that since he knows him in a way no one else can, he must let him go. The closest he gets to being himself again was when Cecilia's cousin, Rose Gibbons, would channel Cecilia's spirit and tell Daniel to stop this path, and that they would be together again. There came a point, however, when hearing Cecilia's voice no longer comforted him, but tormented him. Thus, Daniel resumed his path of alcoholism and fighting. For the last two years of his life, none of his loved ones see him.