[3] It is believed that he was a member of the native Trpimirović dynasty, and some historians have proposed that he is a descendant of Svetoslav Suronja's son Stjepan Svetoslavić which also allowed for the thesis that he began his career as Ban of Slavonia.[4] Others rejected his Trpimirović descent and argued he was a member of some other prominent Croatian noble family possibly from Sidraga županija,[5][6] but his early marriage to Árpád's princes shows he must have been of some extraordinary lineage.[3] In the historical sources are also mentioned his magistro ("teacher") Scestaki (Šestak), and uncle Strezata (Streza) to whom allowed gathering tax in Mosor and from Solin to Bijaći.[3] During the reign of King Peter Krešimir IV, his relative also through the Orseoli family of Venice, older generation of historians conjectured that Zvonimir initially administered Slavonia, specifically the land between the rivers Drava and Sava, with the title of ban.[10] According to Chronicon Pictum, Croatia was also attacked around 1063 by the Carantanian army of Ulric I, who occupied a part of Kvarner and the eastern coast of Istria, the "March of Dalmatia".The pope intervened on behalf of Zvonimir, under threat of excommunication, urging Vecelin to make any complaint to him directly regarding any issues with the king.[35][36][37] This view had been mostly accepted in the historiography since the 16th century, but some historians like Ferdo Šišić and archaeologist Stjepan Gunjača argued in favor of a documented violent death.[38] It is argued that his resting place moved between the Cathedral of Saint Bartholomew in Kapitul near Knin and Church of St. Stephen at Salona (today's Solin) where was the Mausoleum of Croatian Kings.[42] According to the chronicles and historical documents, Croatia subsequently entered a period of 10 years of anarchy without social authority,[43] with various sides and nobles fighting over supremacy in the kingdom.[32][46][47] In reality probably happened both scenarios, with widow Jelena seizing some power and receiving support from a small part of Croatian nobility (Lapčani, Gusići and Kukari among others) which eased Ladislaus's intervention.The written experiences of the First Crusaders in late 1096 show that in the country called Sclavonia and Dalmatia could not find any authority to agree the terms of passage and relations with the people,[55] and there is no mention of Hungarian king on the Baška tablet.[60][61][62] Demetrius Zvonimir is viewed in contemporary Croatia as the last native king who held any real power and is regarded as one of the national heroes from the medieval period.[70] Also, the First Crusade initiative and campaign happened several years after Zvonimir's death, and there's no evidence that the Pope or others before Council of Clermont (1095) were making and taking active measures at European royal courts.[71] Ivo Goldstein argues that during several stages of the creation of the legend, as being the last historically notable Croatian king, were skipped several years of much less known personalities Stephen II and Petar Snačić who lived closer to the time of First Crusade but were linked their years and events to the narrative about Zvonimir, as such for example the violent death with the death of Petar Snačić, fictionally making Zvonimir a contemporary of the First Crusade.[77][78][79] According to Mladen Ančić, the legend which the author of the chronicle re-edited, came to the Polish court with Katarina Šubić who married in 1326 Bolesław III the Generous.[80] Another account, from the Croatian redaction/The Croatian Chronicle dated to the 14-15th century of the 13th century Chronicle of the Priest of Duklja,[81] says that in 1079 (evidence that the anonymous author or copyist mistook Glagolitic letter meaning 80 with Cyrillic meaning 70[82][68]), desiring to heal the East-West Schism Pope Urban II asked Zvonimir, his strongest ally in the Eastern Adriatic, to go on a Crusade liberating Christ's grave.Since its barbarous death can only be explained by cursing, with dark crime of wicked folk, where their fury relents until the heart eases and with murder they take down the king, very healthy, with much power, the pious Zvonimir, distinctly fair and honest, who was their shield against enemies, used to crush the rival doors, mourn, champions, already a leader plies, old and young of Croatian land, because what was first divination of the kingdom and also honour and glory, is now in ruins.After three months of nobles excusing themselves for lack of finances and maritime skills, Zvonimir invited them to go with the Hungarian king by land because of which they angrily attacked him, but was only half-dead.Zvonimir called the notary Simon and in front of the bishop of Knin and others made a testimony – his two daughters were given in trust to nobleman Snazach (Snačić[68]) and the Croatian kingdom to Hungary by accepting their king as his son.[88][89] Ivan Tomašić's Chronicon breve Regni Croatiae from around 1561, in an otherwise identical account to the others (but naming Zvonimir in Hungarian-style Zorobel and dating it to the year 1057), names the assassins as the king's personal secretary as well as chaplain Tadija Slovinac, who entered the king's tent located by the Basillica of Saint Cecillia in Petrovo polje and killed him in his sleep upon the insistence of the population who did not want to go to war to a land faraway from their homeland, wives and children.