Church Councils of Split is a collective name for several church councils that were held in the town of Split in the early Middle Ages, and whose conclusions have significance for the whole territory of the early Croatian Kingdom. Two most important Councils were convened by Pope John X in years 925 and 928.
Since 920's the Byzantine Empire was considerably weakened so Emperor Romanos I gave management over Dalmatia to the Croatian King Tomislav. This is confirmed by the fact that the Byzantine governor of Dalmatia wasn't listed as one of the participants on the official council documents. Tomislav needed to connect the church authorities in Croatia and Dalmatia so he could easily integrate Dalmatia into his Kingdom.
First church council of Split was convened by Pope John X in year 925. The main task of this Council was solving issues of the ecclesiastical jurisdiction in the Kingdom of Croatia and the eradication of the Slavic language and the Glagolitic alphabet in the liturgy.
Just before the beginning of the Council session the Pope sent two legacies, John-Bishop of Ancona and Leon-Bishop of Palestine, to give one invitation letter to each of the Slavic rulers, Archbishop of Split and other Dalmatian bishops.
During the Council session, which was attended by the Croatian King Tomislav and Michael of Zahumlje, and unnamed Croatian and Serbian nobles (Croatorum atque Serborum proceribus), various ecclesiastical organization and discipline issues were discussed, while 15 conclusions were adopted. Most important question was one about the seat of the newly founded ecclesiastical province of Croatia and Dalmatia.