Pellegrino Luigi Odoardo Rossi was an Italian economist, politician and jurist. He was an important figure of the July Monarchy in France, and the minister of justice in the government of the Papal States, under Pope Pius IX.

Pope Pius IX was head of the Catholic Church from 1846 to 1878. His reign of 32 years is the second longest of any pope in history, behind that of Saint Peter. He was notable for convoking the First Vatican Council in 1868 and for permanently losing control of the Papal States in 1870 to the Kingdom of Italy. Thereafter, he refused to leave Vatican City, declaring himself a "prisoner in the Vatican".