marrow
to the marrow to your innermost being.
☞ Marrow is the soft, fatty substance found in the cavities of bones.
2012Daily Telegraph People may think of you as an outsider ('Phil the Greek', born in Corfu), but your mother, Princess Alice, was born in Windsor Castle, the daughter of Princess Victoria, one of Queen Victoria's favourite granddaughters .… You are royal to the marrow-related to kings, queens, emperors, kaisers, tsars.