According to Anđelko Mijatović, it is generally believed that the epic personality of Petar Mrkonjić is a historical figure, and that he was born in Imotski. He is possibly the same person as Petar Imoćanin ("Petar from Imotski"), who lived in the mid-17th century and is said to have greatly damaged properties of the Republic of Ragusa, after which the Ragusans urged the Venetians to stop him, as he was a Venetian subject.
Vuk Stefanović Karadžić had found no historical documents on Petar Mrkonjić. Folklorist Stjepan Grčić did not believe Petar Mrkonjić was a historical figure. Mrkonjić has become the subject of poems and Croatian patriotic songs.
One of the earliest mentions of Mrkonjić were written by the Venetian-Croatian friar and poet Andrija Kačić Miošić (1704-1760) in Vitezovi Imotske krajine.
Da je komu pogledati bilo
ljutu zmiju Petra Mrkonjića: u njega su oči sokolove, a desnica Miloš Kobilića! Često ide na Bosnu ponosnu, vodi roblje na skelu makarsku ter prodaje Turke u Latine i lijepe bule i kadune. Ni to Petru dosta ne bijaše, već junačke glave odsicašest
To svidoče starci od krajine, da bijaše junak od starine,
a najveće pisme i popivke, kojeno se od njega pivaju: junak biše Petre Mrkonjiću,
ognjenoga rata od Kandije. In Serbian epic poetry, he has a hero status along with other hajduks such as Starac Vujadin, Pecija, Golub, Starina Novak, Bajo Pivljanin, and others
He is also the subject of a poem by Serbian linguist Vuk Stefanović Karadžić (1787-1864) in Jaut-beg i Pero Mrkonjić.
During the Great Eastern Crisis (1875-1878), set off by a Serb uprising against the Ottoman Empire in 1875 in Bosnia and Herzegovina (Herzegovina Uprising (1875-1877)), Prince Peter adopted the nom de guerre of hajduk Petar Mrkonjić of Ragusa, and joined the Bosnian Serb insurgents as a leader of a guerilla unit In 1925 the "Organization of Serbian Chetniks - Petar Mrkonjić" was founded, though it was banned by King Alexander I of Yugoslavia four years later when he instituted a dictatorship. In World World War II, there was a Chetnik command named "Petar Mrkonjić", with 700 fighters.
Babić formed the paramilitary Petar Mrkonjić-brigade in April 1992.
The "Medal of Petar Mrkonjić" was also given by Republika Srpska.
