Branimir (Branimiro) was a ruler of Duchy of Croatia who reigned as duke (knez) from 879 to c. 892. His country received papal recognition as a state from Pope John VIII on 7 June 879. During his reign, Croatia retained its sovereignty from both Carolingian and Byzantine rule and became de jure independent. His rule marks the first real peak of early medieval Croatia. It was characterized by establishing closer relations with the Holy See, ecclestical re-organization in the former Roman province of Dalmatia, Christianization, and (re)construction of churches. Branimir is mentioned, for the period, in many reliable primary and secondary written and ephigraphic sources. In 879, "certain Slav of the name Branimir" reportedly had weak Duke Zdeslav, a supporter of the Byzantine Empire, killed near Knin in a rebellion that he led, per John the Deacon's Chronicon Venetum et Gradense (early 11th century). In the Epistolae Ioannis VIII are preserved five papal letters sent between 879 and 882. During the solemn divine service in St. Peter's church in Rome in 879, Pope John VIII gave his blessing to the duke, his authority and the whole Croatian people and country about which he informed Branimir in the first letter. The Pope brought the very decision on 21 May 879, and confirmed it in his letter on 7 June 879 (mentioning him as Dilecto filio Branimir). As the blessing was reported by Pope himself twenty days later it probably had a great meaning for the time, recognizing Croatia as a relevant part of medieval Christian Europe, and sovereign state. In the third letter of the same month Branimir is once again mentioned (as principis ... Branimir), and the letter is titled to all honorable priests and all the people (Omnibus uenerauilibus/sacerdotibus et uniuerso populo). After 880, Branimir did not succumb to pressure of recognizing sovereignty of Charolingian Emperor Charles the Fat, even after the emperor made years long alliance with Venetians against Croatia.