Eamon Duffy writes:
The reputation of Eugenio Pacelli, who reigned as Pope Pius XII from March 1939 until his death in October 1958, is an object lesson in the fragility of popularity and public esteem. Pacelli was a favoured son of Rome’s ‘black nobility’, the cluster of families whose 19th-century fortunes were built on service to the papacy. In these circles, the Pacellis ranked very high, described by one historian as the most important papal family since the Borgias. Eugenio’s grandfather, Marcantonio, was a key financial administrator under Pope Pius IX until the fall of the Papal States in 1870, and then editor of the official papal newspaper, Osservatore Romano. The future pope’s cousin Ernesto was the banker who directed the papacy’s investment policy under Pope Leo XIII, and was largely responsible for the stabilisation of its finances after the loss of the papal territories to the Italian state. Eugenio’s older brother, Francesco, was the lawyer who handled most of the negotiations for the Lateran Pact of 1929, the treaty that normalised the papacy’s relations with Fascist Italy and established the Vatican City State, and with it the political arrangements that still safeguard the spiritual autonomy of the papacy in a secular Italy.