Penny dreadfuls were cheap, sensational fiction popular in the 19th century, particularly in England. Priced at a penny, these serialized stories were often published in weekly installments, making them accessible to a wide audience. They typically featured thrilling tales of crime, horror, and adventure, appealing to the working class. These publications often included illustrations and were known for their melodramatic plots and exaggerated characters. Notable examples include The String of Pearls, which introduced the character Sweeney Todd, and Varney the Vampire. Penny dreadfuls played a significant role in the development of popular literature and paved the way for modern genres like horror and detective fiction.