With the 1840 novels finished, Ainsworth began to write "Old St. Paul's, A Tale of the Plague and the Fire". The work ran in "The Sunday Times" from 3 January 1841 to 26 December 1841, which was an achievement as he became one of the first writers to have a work appear in a national paper in such a form. His next works, "Windsor Castle" and "The Miser's Daughter", appeared in 1842. The first mention of "Windsor Castle" comes in a letter to Crossley, 17 November 1841, in which Ainsworth admits to writing a novel about Windsor Castle and the events surrounding Henry VIII's first and second marriages. "The Miser's Daughter" was published first, starting with the creation of "Ainsworth's Magazine", an independent project that Ainsworth started after leaving "Bentley's Miscellany". To create the magazine, Ainsworth teamed with Cruikshank, who served as the illustrator. Cruikshank moved his efforts from his own magazine, "The Omnibus", to the new magazine, and an advertisement for it appeared in December 1841, saying that the first issue would be published on 29 January 1842. The opening of the magazine was welcomed by contemporary members of the press, which only increased as the magazine proved to be successful. "Ainsworth's Magazine" marked the height of his career.