Dečani polijelej. Serbian historian Stanoje Stanojević argued that it entered its use in 1345, with Stefan Dušan's elevation to Emperor. In the Middle Ages, both the "Greek style", with closed fire-steels (β–B), and the "Serbian syle", with open fire-steels (C-S), were used in Serbia. A 1439 map by Gabriel de Vallseca used both the Serbian cross and eagle when depicting Serbia. Early modern and modern history In South Slavic heraldic sources (also known as "Illyrian Armorials"), the Serbian cross is found in the Korenić-Neorić Armorial (1595), which shows the coat of arms of Serbia (Svrbiae) as a white cross over a red background, with four firesteels, also depicting the Mrnjavčević noble house with the same design, with inverted colours and the Serbian eagle in the center of the cross. According to Mavro Orbini (1607), it was used by Vukašin Mrnjavčević (King, 1365–1371) and Lazar Hrebeljanović (Prince, 1371–1389). Next, it is found in the Belgrade Armorial II (ca. 1600–1620), the Fojnica Armorial (between 1675 and 1688), the Armorial of Stanislaus Rubcich (ca. 1700), and Stemmatographia (1741), while still continuing to be used in foreign heraldic sources. The Metropolitanate of Karlovci, established in 1691, adopted it in its seal. After the Serbian Revolution, the Serbian cross then appeared on all official Serbian coats of arms, except the Serbian coat of arms adopted in 1947, which had the cross removed, leaving four stylized S; this was done symbolically by the Yugoslav government to "socially curtail and politically marginalize religious communities and religion in general". During WWII, The Serbian cross was used in the Nazi backed puppet government, Government of National Salvation Flag (1941–1944). Miloš Obrenović adopted the Serbian cross as the military flag when forming the first units of the regular army in 1825. The double-headed eagle and the cross are the main heraldic symbols which represent the national identity of the Serbian people, and the Serbian cross symbol has been frequently used in Serb heraldry. Serbian popular tradition attributes the symbol to St. Sava, 12th century metropolitan of Žiča and Archbishop of Serbs. St. Sava is also associated with the motto Only Unity Saves the Serbs (). The memorial park in Tekeriš, where the first battle of World War I was fought, the monument has "18-VIII-1914" and Samo sloga srbina spasava inscribed. A monument in Šamac, Republika Srpska, Bosnia-Herzegovina for the Serbs who fought and died in the Bosnian war, has the