Massinger's sources for Italian history in the relevant era were William Thomas's The History of Italy (1561) and Francesco Guicciardini's Historia d'Italia, most probably in Geoffrey Fenton's translation (third edition, 1618).
Milan | Duke University | Duke Ellington | Duke | Duke of Wellington | Prince William, Duke of Cambridge | A.C. Milan | Duke of York | University of Milan | Duke of Norfolk | Duke of Edinburgh | Duke of Burgundy | Inter Milan | Prince Arthur, Duke of Connaught and Strathearn | George Villiers, 1st Duke of Buckingham | Prince Andrew, Duke of York | Duke of Northumberland | Alfred, Duke of Saxe-Coburg and Gotha | Prince Richard, Duke of Gloucester | Prince Frederick, Duke of York and Albany | George Duke | Charles Lennox, 2nd Duke of Richmond | Milan Kundera | Louis Philippe II, Duke of Orléans | Edward Seymour, 1st Duke of Somerset | Philippe II, Duke of Orléans | John Frederick II, Duke of Saxony | Hugh Grosvenor, 2nd Duke of Westminster | George Monck, 1st Duke of Albemarle | Frederick Schomberg, 1st Duke of Schomberg |
In 1401, while serving as the Florentine ambassador to Bavaria, he, his brothers, and their descendents were ennobled by Rupert, King of Germany, after having saved his life by thwarting a poisoning attempt by the Duke of Milan.