Nevertheless, at the court of Svatopluk, who himself professed the Latin Rite, intrigues against Methodius and the liturgy in Old Church Slavonic gathered strength. Svatopluk sent John of Venice, a known opponent of the Slavic liturgy, to Rome in 879 to achieve a settlement of ecclesiastical differences. In a letter addressed to Methodius in the same year, the Pope sharply rebuked him for using Slavonic in church services. Methodius, however, travelled to Rome in 880, together with a Moravian delegation. Under his influence Pope John VIII changed his mind and in a letter, known for its incipit, "Industriae tuae", the Pope repeated that Mass was to be sung in Latin whenever requested, but he also allowed the use of Slavonic liturgy. The letter also confirmed the decision taken by the Holy See during Rastislav's reign to create an archdiocese for Great Moravia. Upon Svatopluk's request the Pope promoted a German priest, Wiching, to be Bishop of Nitra, but he added that the new Bishop and all the clerics in Great Moravia were expected to be obedient to Methodius, who remained the head of the church in Svatopluk's realms.