Winston Churchill, John F. Kennedy, and Princess Diana were all descendants of Gerald de Windsor and Princess Nest of Wales. For hundreds of years the origin of the ancestors of Gerald de Windsor has been debated, with some arguing that they were Anglo-Normans, and others arguing that they were originally from Florence, Tuscany, and were Italian. This paper, which includes a full bibliography, aims to set the record straight once and for all. The author presents new facts and discusses primary documents that have been overlooked or ignored by other researchers, including documents written in the Italian language. He makes a strong case that the Gherardini of Florence were, in fact, the ancestors of the Geraldines, or Fitzgeralds, the Fitzmaurices, the Desmonds, the Keatings, and the rest. His arguments are strengthened by the results of the DNA tests of the descendants of a Keating.