With the fall of the Carolingian Empire, the Franks ceased to be a major power in the Adriatic, while the Republic of Venice grew in power in Dalmatia, beginning with Doge Pietro Tradonico. Around 923 AD, Tomislav of Croatia, the Byzantine Emperor and the two church patriarchs were involved a deal that transferred the control of the Byzantine Dalmatian cities to the new Croatian kingdom. This started a series of similar maneuvers and the Croatian–Bulgarian Wars, during which the Byzantine Emperors of the Macedonian dynasty maintained varying degrees of control over the Dalmatian cities. The Church also endured an analogous internal conflict between the rival dioceses of Spalatum and Nin. The Venetian maritime power was obstructed by the Narentines and the Croats until Pietro II Orseolo who successfully intervened in 998 and 1000, and arranged two important royal marriages with both the Croats and the Byzantines. Under Domenico I Contarini, Venice retook Jadera. Croatia had another brief period of control over the Dalmatian city-states under Peter Krešimir IV, but the invasion of the Normans shifted the balance of power back to the Venetians. Indeed, in 1075 AD the Norman "Count Amico" invaded Croatia from southern Italy, on behalf of the Dalmatian cities (by invitation to protect them from Croatian domination). Amico besieged Arbe for almost a month (late April to early May). He failed to take the island, but he allegedly did manage to capture the Croatian king himself (whose mother was the daughter of Doge Pietro Orseolo) at an unidentified location. In return for liberation, he was forced to relinquish many cities, including both his Croatian capitals, as well as Zara, Spalatum, and Tragurium. However, over the next two years, the Venetians banished the Normans and secured the Dalmatian cities for themselves. In the south of the Dalmatia Theme, the city of Ragusa, one of the main Dalmatian city-states but still under Byzantine control, started to grow in importance, and its Church diocese was elevated to an archbishopric in 998 AD. In the early 11th century, Byzantine control over the eight Dalmatian city-states started to be contested by the Serb principality of Dioclea, whose ruler Jovan Vladimir took control of Bar, near the border with the Theme of Dyrrhachium.