Benedict VIII — born Theophylact of Tusculum, son of Gregory I, Count of Tusculum — was one of the most consequential popes of the early 11th century. The Tusculani noble family of Latium produced three successive popes (Benedict VIII, John XIX, Benedict IX) — the Tusculan Papacy of the early 11th century.
He was elected pope on May 18, 1012, against the rival candidate of the Crescentii family. His twelve-year pontificate restored the dignity of the papal office after the depredations of the late-10th-century saeculum obscurum.
He allied with the Saxon-Salian Emperor St. Henry II — crowning Henry and his wife St. Cunigunde as Holy Roman Emperor and Empress at the basilica of St. Peter on Sunday February 14, 1014. The 1014 imperial coronation instituted the continuous tradition of Saxon-Salian and Hohenstaufen imperial coronations at Rome by the pope — the ritual pattern that would extend through the medieval centuries.
Most consequentially, at the 1014 imperial coronation, Benedict VIII — at the request of Emperor Henry II — for the first time permitted the singing of the Nicene Creed with the Filioque clause ('and the Son') at the Mass in Rome. The Filioque addition — previously practised in the Frankish and German Catholic Churches but not at Rome — became the permanent Roman Mass practice from 1014, precipitating the doctrinal escalation that would contribute to the definitive East-West Schism of 1054.
He convened the Synod of Pavia (1022) — the principal reform synod of his pontificate, addressing the scandals of clerical concubinage and simony, anticipating the Gregorian Reform of the mid-11th century.
He negotiated the Roman naval cooperation with the rising Norman power in southern Italy — supporting the Norman knight Melus's early-Norman campaigns in Apulia against the Byzantine Catepanate, the distant institutional pre-history of the Norman conquest of southern Italy that would culminate in the Norman Kingdom of Sicily.
He died on April 9, 1024.