Question: The father of Pietro de' Medici was the Duke of Florence between what years?
Sentence (from "Cosimo I de' Medici, Grand Duke of Tuscany"): Cosimo I de' Medici (12 June 1519 – 21 April 1574) was the second Duke of Florence from 1537 until 1569, when he became the first Grand Duke of Tuscany.
Relevant evidence: Yes