During the reign of Krešimir IV (1058–1074), the medieval Croatian kingdom reached its territorial peak. Krešimir managed to get the Byzantine Empire to confirm him as the supreme ruler of the Dalmatian cities, "i.e.", over the Theme of Dalmatia, excluding the theme of Ragusa and the Duchy of Durazzo. He also allowed the Roman curia to become more involved in the religious affairs of Croatia, which consolidated his power but disrupted his rule over the Glagolitic clergy in parts of Istria after 1060. Croatia under Krešimir IV was composed of twelve counties and was slightly larger than in Tomislav's time. It included the closest southern Dalmatian duchy of Pagania, and its influence extended over Zahumlje, Travunia, and Duklja. The župans (heads of counties) had their own private armies. The names of court titles in their vernacular form appear for the first time during his reign, such as "vratar" ("door-keeper") Jurina, "postelnik" ("chamberlain") and so on. The Roman Catholic Church reforms, which imposed a ban on the use of Slavonic liturgy and introduced Latin as obligatory, were confirmed by Pope Alexander II in 1063. This led to a rebellion in the kingdom by the counter-reform camp, primarily in the Kvarner region. While King Krešimir IV sided with the Pope, expecting a victory of the pro-Latin clergy, support for the counter-reform clergy was provided by Antipope Honorius II. The rebellion was led by a priest named Vulfo on the island of Krk. Although the rebels were quickly suppressed, Slavonic liturgy held out in the Kvarner region, as well as the use of Glagolitic script.