The Treaty of Den Haag (also known as the Treaty of The Hague) was signed on February 17, 1720. The treaty ended the War of the Quadruple Alliance, a conflict that arose between King Philip V of Spain and an alliance of of Great Britain, France, Austria and the Dutch Republic. Philip was confirmed king of Spain by the Treaty of Utrecht in 1713, ending the War of the Spanish Succession. However, in that treaty Spain lost its territories in Italy and the Netherlands. Philip, intent on winning back his former Italian possessions, invaded Sicily in 1718, which had been ceded to the Duchy of Savoy. In response, the Quadruple Alliance was formed and defeated Spain. In the Treaty of Den Haag, Philip agreed to abandoned his Italian claims, but won the assurance from Austria that the Duchy of Parma would be succeeded by his son, Charles, upon the extinction of the Farnese line. This came to pass in 1731, but Philip broke the treaty during the War of the Polish Succession, when Spanish forces invaded Sicily.
In another provision of the Treaty of Den Haag, Duke Victor Amadeus II of Savoy agreed to exchange Sicily with Austria, for the island of Sardinia after which he was known as the King of Sardinia.
