English noted family member, as the illegitimate daughter of the poet George Gordon, Lord Byron and Claire Clairmont, who initially named her Alba, meaning “dawn”, or “white.” At first she lived with her mother, her mother’s stepsister, Mary Shelley, and Mary’s husband Percy Bysshe Shelley. When she was fifteen months old she was turned over to Byron, who changed her name to Allegra.
Throughout the pregnancy, Clairmont had written long letters to Byron, pleading for his attention and a promise to care for her and the baby, sometimes making fun of his friends, reminding him how much he had enjoyed making love to her, and sometimes threatening suicide. Byron, who by this time hated her, ignored the letters. The following year, Clairmont and the Shelleys left England and journeyed once more to Byron, who now resided in Italy. Clairmont felt that the future Byron could provide for their daughter would be greater than any she herself would be able to grant the child and, therefore, wished to deliver Allegra into his care.
Upon arriving in Italy, Clairmont was again refused by Byron. He arranged to have Allegra delivered to his house in Venice and agreed to raise the child on the condition that Clairmont keep her distance from him. Clairmont reluctantly gave Allegra over to Byron.
Mary Shelley had called the baby Allegra “the little Commodore” because of her sturdy body and alert, intelligent look. Byron was also pleased with Allegra’s resemblances to himself in appearance and temperament. As she grew older, Allegra demonstrated a talent for acting and singing. However, Byron placed her with foster families and later in a Roman Catholic convent in Bagnacavallo, Italy.
By March 1822, it had been two years since Clairmont had seen her daughter. She plotted to kidnap Allegra from the convent and asked Shelley to forge a letter of permission from Byron. Shelley refused her request. Byron’s seemingly callous treatment of the child was further vilified when Allegra died in the convent at age five of typhus or malaria on 20 April 1822. Clairmont held Byron entirely responsible for the loss of their daughter and hated him for the rest of her life.
Link to Wikipedia biography