The Byzantine brothers, Constantine (Cyril) and Methodius, visited Rome in 867. At the end of the year, Pope Hadrian II (r. 867–872) sanctioned their translations of liturgical texts and ordained six of their disciples as priests. The pope informed three prominent Slavic rulersRastislav, his nephew, Svatopluk, and Koceľ, who administered Lower Pannoniaof his approval of the use of the vernacular in the liturgy in a letter of 869. In 869 Methodius was sent by the pope to Rastislav, Svatopluk and Kocel, but Methodius visited only Kocel, who sent him back to the pope. Hadrian then consecrated Methodius as archbishop with the title of Metropolitan of Sirmium to "the seat of Saint Andronicus",--"i.e.", the see of Sirmium. At the beginning of the 9th century, many Carantanians (Alpine Slavs), ancestors of present-day Slovenians, settled in the Lower Pannonian region, also known as the Balaton Principality, which was referred to in Latin sources as Carantanorum regio, or "The Land of the Carantanians". The name Carantanians (Quarantani) was in use until the 13th century. Kocel's decision to support Methodius represented a complete break with his father's pro-Frankish policy. Svatopluk had by that time been administering what had been the Principality of Nitra, under his uncle Rastislav's suzerainty, but contemporaneous documents do not reveal the exact location of Svatopluk's successorial territory. Frankish troops invaded both Rastislav's and Svatopluk's realms in August 869. According to the "Annals of Fulda", the Franks destroyed many forts, defeated Moravian troops and seized loot. However, they could not take Rastislav's main fortress and withdrew.