Gian Gastone de' Medici, Grand Duke of Tuscany

Born the second son in 1671, Gian Gastone de' Medici wasn't meant to rule — but his elder brother Ferdinando died before their father, Cosimo III, leaving him next in line. His sister brokered his 1697 marriage to the wealthy widow Anna Maria Franziska of Saxe-Lauenburg; the two loathed each other and produced no children. When he finally succeeded Cosimo in 1723, he reversed his father's rigid policies: he lifted taxes on the poor, repealed laws restricting Jews, and ended public executions. But the dynasty was hollow — no male heirs, and the great powers ignored Cosimo's wish for Gian Gaston…