Zastrozzi was written by Percy Bysshe Shelley (1792–1822) at age of 17 during his last year at Eton, and it was published in 1810 when he was at Oxford. In the first edition, he was identified on the title page only by his initials. In St. Irvyne, published shortly afterward, he was identified as "A Gentleman of the University of Oxford."
Both novels are of interest today as early artifacts of the age of the Gothic horror novel—the era that not long afterwards produced the magnificent Frankenstein by Shelley's wife Mary. A brief but complex tale of romance and revenge, Zastrozzi  —like its companion, St. Irvyne — was praised by some critics and derided by others. Both stories manifest the creative flair of their young author, who went on to become one of the greatest poets in the English language during his short life.