In 1545, Paul handed over, from land once belonging to the Papal States, further territories in northern Italy to his son, who took the additional title of Duke of Parma. Paul thus established his family as an Italian ducal dynasty, a project at which the Borgia Pope Alexander VI had failed. Two years later, Pier Luigi was assassinated by his new subjects under a Spanish mandate. Despite intrigues by Charles V, the Pope reacted promptly and soon established Ottavio, Pier Luigi's son, on the ducal throne. He secured this by marrying Ottavio (1547–86) to the eldest illegitimate daughter of Charles V, Margaret. Ottavio was given the additional title of Duke of Piacenza and initially established his court there, where work was begun on a huge Farnese palace on the banks of the River Po. However, during construction, and probably in response to political intrigues by the Piacentine nobility, Ottavio Farnese moved his court to Parma, where he had the Palazzo della Pilotta constructed in 1583.