Born Camillo Borghese in Rome in 1550, Paul V reigned as pope from 1605 until his death in 1621. He financed the completion of St. Peter's Basilica, and in 1611 he honored Galileo Galilei as a member of the Papal Accademia dei Lincei and supported his discoveries. LS in Italian, signed “Camillo Borghese,” one page, 7.5 x 10, July 20, 1590. Untranslated letter signed at the conclusion by the future Pope Paul V using his given name. Archivally matted and framed with a portrait and caption to an overall size of 21 x 17. In fine condition.