The Serbian Cross () is a national symbol of Serbia, part of the coat of arms and flag of Serbia, and of the Serbian Orthodox Church. It is based on the tetragrammic cross emblem/flag 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). It is composed of a cross symbol with four "fire striker" shapes, originally four Greek letters beta (Β). Serbian tradition attributes the letters to Saint Sava, the 13th-century Metropolitan of Žiča and Archbishop of the Serbs. Popular tradition also interprets the four "fire striker" shapes as four Cyrillic letters "S" (С), for the motto Samo sloga Srbina spasava (, meaning "Only Unity Saves the Serbs"). The double-headed eagle and the cross are the main heraldic symbols which have represented the national identity of the Serb people across the centuries. History Middle Ages Crosses with firesteels have been used since Roman times, 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) 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 (=Jesus Christ), help the King (; ). It was used in flags and coins. The symbol appear on the Imperial flag divellion (διβελλιον) used in front of all other banners, recorded by Pseudo-Kodinos ( 1347–68) wrongly as "a cross with firesteels" (), and depicted in the Castilian Conosçimiento de todos los reynos atlas ( 1350). As Alexander Soloviev writes, the use of letters in western heraldry is nonexistent. The oldest preserved historical source of the cross used in Serbia is from the Dečani oil-lamp (Dečanski polijelej), which was a gift to King Stefan Milutin (r. 1282–1321), the ktetor (founder) of Visoki Dečani, now preserved at the Monastery of Prohor Pčinjski. Stojan Novaković argued that the recorded use of the Serbian cross, as a national symbol, began in 1397, during the rule of Stefan Lazarević. It was possibly derived from the