Stephen, name of 9 popes. Stephen I (reigned 254–57), who died during Emperor Valerian's persecutions, defended the validity of the baptism of heretics, a stance St. Cyprian of Carthage denounced. Stephen II (reigned 752–57) was supported by Pepin the Short in his defeat of the Lombards. The Papal States were founded with land gifts from Pepin. Controversy over papal elections dominated the reign (768–72) of Stephen III. Stephen IV (reigned 816–17) crowned Louis I emperor (establishing a prerogative of the papacy) and strengthened links with the Franks. Stephen VI (reigned 896–97) declared void the reign of his predecessor, Formosus, but was himself imprisoned and strangled. His rule marked the papacy's lowest point. Stephen IX (b.1000; reigned 1057–58) continued the reforms of Leo IX, enforcing priestly celibacy and attacking simony. But he failed to stop the rift between the Eastern and Western churches.