"Margherita de´ Medici (31 May 1612 – 6 February 1679) was Duchess of Parma and Piacenza by her marriage to Odoardo Farnese, Duke of Parma. Margherita was regent of Piacenza in 1635, and regent of the entire duchy from 1646 until 1648 during the minority of her son." - (en.wikipedia.org 13.12.2020)