Sidney Sonnino was one of the most authoritative exponents of Italian liberalism. An opponent of Giolitti, he was twice Prime Minister (1906 and 1909-1910). He was Foreign Minister (1914-1919) and signed the Treaty of London. An attentive reformer of the agricultural system, he was a staunch supporter of universal suffrage. The Castello di Montespertoli is located only 20 km from Florence, within easy reach of Pisa and Siena. King Umberto I, Vittorio Emanuele III, D'Annunzio and Giolitti were his illustrious guests. The oldest parts of the castle are the thirteenth-century tower and chapel. It is now an home to Baron Alessandro and Baroness Caterina de Renzis Sonnino that, in the over more than 57 hectares of the estate, produce olive oils and wines Chianti Montespertoli D.O.C.G. They set up the Sidney Sonnino Study Centre. The Archive keep some documents about nineteenth-century Italy and the First World War. The rooms in which the politician lived have been preserved intact, as well as his vast library.