One key component of magical writings in the Renaissance was the spread of the mystical system of Kabbalah. Johannes Trithemius studied medieval magical manuscripts as well as Kabbalah and wrote a work called "Steganographia" (Secret Writing) in 1499, which was published in 1606. Trithemius’s had many Renaissance successors who would attribute many ideas in their grimoires to "Steganographia" (Reeds Introduction). Image Source: Esoteric Archives.
Giuliano de' Medici Duke of Nemours Artist: Copy after Raphael century) Medium: Tempera and oil on canvas Dimensions: 32 x 26 in. x 66 cm) Classification: Paintings Credit Line: The Jules Bache Collection, 1949 Accession Number:
Catherine de Medici and her children: Charles IX, Henry III, Francis the duke dAlenon, and Margaret queen of Navarre. Once in the collection of Horace Walpole at Strawberry Hill, it is now in the Victoria and Albert.