imposed their rule (1440–1449) through their associated families of Pallavicino, Rossi, Sanvitale and Da Correggio. These created a kind of new feudalism, building towers and castles throughout the city and the land. These fiefs evolved into truly independent states: the Landi governed the higher Taro's valley from 1257 to 1682. The Pallavicino seignory extended over the eastern part of today's province, with the capital in Busseto. Parma's territories were an exception for Northern Italy, as its feudal subdivision frequently continued until more recent years. For example, Solignano was a Pallavicino family possession until 1805, and San Secondo belonged to the Rossi well into the 19th century. Modern era Between the 14th and the 15th centuries, Parma was at the centre of the Italian Wars. The Battle of Fornovo was fought in its territory. The French held the city in 1500–1521, with a short Papal parenthesis in 1512–1515. After the foreigners were expelled, Parma belonged to the Papal States until 1545. In that year the Farnese pope, Paul III, detached Parma and Piacenza from the Papal States and gave them as a duchy to his illegitimate son, Pier Luigi Farnese, whose descendants ruled in Parma until 1731, when Antonio Farnese, last male of the Farnese line, died. In 1594 a constitution was promulgated, the University enhanced and the Nobles' College founded. The war to reduce the barons' power continued for several years: in 1612 Barbara Sanseverino was executed in the central square of Parma, together with six other nobles charged of plotting against the duke. At the end of the 17th century, after the defeat of Pallavicini (1588) and Landi (1682) the Farnese duke could finally hold with firm hand all Parmense territories. The castle of the Sanseverino in Colorno was turned into a luxurious summer palace by Ferdinando Bibiena. In the Treaty of London (1718) it was promulgated that the heir to the combined Duchy of Parma and Piacenza would be Elisabeth Farnese's elder son with Philip V of Spain, Don Carlos. In 1731, the fifteen-year-old Don Carlos became Charles I Duke of Parma and Piacenza, at the death of his childless great uncle Antonio Farnese. In 1734, Charles I conquered the kingdoms of Naples and Sicily, and was crowned as the King of Naples and Sicily on 3 July 1735, leaving the Duchy of Parma to his brother Philip (Filippo I di Borbone-Parma). All the outstanding art collections of