Eugenio Maria Giuseppe Giovanni Pacelli was born on 2 March 1876 in Rome into a family of intense Catholic piety with a history of ties to the papacy (the "Black Nobility"). His parents were Filippo Pacelli (1837–1916) and Virginia (née Graziosi) Pacelli (1844–1920). His grandfather, Marcantonio Pacelli, had been Under-Secretary in the Papal Ministry of Finances and then Secretary of the Interior under Pope Pius IX from 1851 to 1870 and helped found the Vatican's newspaper, L'Osservatore Romano in 1861. His cousin, Ernesto Pacelli, was a key financial advisor to Pope Leo XIII; his father, Filippo Pacelli, a Franciscan tertiary, was the dean of the Roman Rota; and his brother, Francesco Pacelli, became a lay canon lawyer and the legal advisor to Pope Pius XI, in which role he negotiated the Lateran Treaty in 1929, the pact with Benito Mussolini, bringing an end to the Roman Question.
Eugenio Pacelli at the age of six in 1882
Together with his brother Francesco and his two sisters, Giuseppina and Elisabetta, he grew up in the Parione district in the centre of Rome. Soon after the family had moved to Via Vetrina in 1880 he began school at the convent of the French Sisters of Divine Providence in the Piazza Fiammetta. The family worshipped at Chiesa Nuova. Eugenio and the other children made their First Communion at this church and Eugenio served there as an altar boy from 1886. In 1886 too he was sent to the private school of Professor Giuseppe Marchi, close to the Piazza Venezia. In 1891 Pacelli's father sent Eugenio to the Liceo Ennio Quirino Visconti Institute, a state school situated in what had been the Collegio Romano, the premier Jesuit university in Rome.
In 1894, aged 18, Pacelli began his theology studies at Rome's oldest seminary, the Almo Collegio Capranica, and in November of the same year, registered to take a philosophy course at the Jesuit Pontifical Gregorian University and theology at the Pontifical Roman Athenaeum S. Apollinare. He was also enrolled at the State University, La Sapienza where he studied modern languages and history. At the end of the first academic year however, in the summer of 1895, he dropped out of both the Capranica and the Gregorian University. According to his sister Elisabetta, the food at the Capranica was to blame. Having received a special dispensation he continued his studies from home and so spent most of his seminary years as an external student. In 1899 he completed his education in Sacred Theology with a doctoral degree awarded on the basis of a short dissertation and an oral examination in Latin.