The picture shows a study for the fortifications of Porta al Prato d'Ognissanti in Florence. In political terms, Michelangelo was an enigmatic personality. Although he was trained in the House of Medici, he was, after the family's expulsion from Florence in 1526, to become the head of fortification works in the last phase of the republican government. But his plans for fortification were never realised, since the Medicis succeeded in returning in 1530.