The Serbian cross is a national symbol of Serbia, part of the Coat of arms of Serbia, flag of Serbia and the Serbian Orthodox Church. Essentially, it is cross surrounded with a four signs of fire striker (or fire steel) what is a piece of high carbon or alloyed steel from which sparks are struck by the sharp edge of chert or similar rock.
For modern fire strikers, also called "artificial flints", see ferrocerium.
Serbian cross although older symbol, have similarity with the tetragrammatic cross emblem of the Byzantine Palaiologos dynasty, with the difference that in Serbian use the cross is usually white on a red background, rather than gold on a red background (though it can be depicted in gold as well).
Popular interpretation about four stylized letters on each of corners of Serbian cross cross symbol state that those letters represent S (С) in Cyrillic alphabet. The Serbian tradition attributes the symbol to St. Sava, 12th century metropolitan of Žiča and Archbishop of Serbs, creation of the popular motto from those four letters, Only Unity Saves the Serbs (Serbian: Само слога Србина спасава/Samo sloga Srbina spasava).
The double-headed eagle and the cross are the main heraldic symbols which represent the national identity of the Serbian people across the centuries.
Crosses with firesteels have been used since time immemorial, in Proto-Slavic and later in Roman times, in the Middle Ages and the Viking Age. as symbols, but not as coats of arms or emblems. Some historians connect it with the labarum, the Imperial flag of Constantine the Great (r. 306–337). In the 6th century the cross with four fields (with either letters or heraldry), tetragramme, appear on Byzantine coins. The symbol was adopted by the First Crusaders since the first event, People's Crusade (1096).Michael VIII Palaiologos (1261–1282) adopted the symbol when he resurrected the Byzantine Empire, with the initials (letters β) of the imperial motto of the Palaiologos dynasty: King of Kings, Ruling Over Kings (βασιλεὺς βασιλέων, βασιλεύων βασιλευόντων Basileus Basileōn, Basileuōn Basileuontōn). It was used in flags and coins.