Slava (celebration day of the Patron Saint) of the Sovereign Military Order of the Dragon is Vidovdan (St. Vitus Day), which is celebrated on the 28th of June. St. Vitus Day is the day when the Battle of Kosovo took place, in 1389, and represents one of the foundations of Serbian history. This was chosen to be the Slava of the Order, because HRH Prince Aleksandar Karadjordjevic signed the founding charter of the Sovereign Military Order of the Dragon on Vidovdan (St. Vitus Day), 2011. Patron saint of the Sovereign Military Order of the Dragon is the Great Martyr King Lazar Hrebeljanovic, the Serbian ruler who died on the 28th of June, 1389, in the Battle of Kosovo, willingly choosing the heavenly kingdom, thus becoming a symbol for the whole history. This saint is celebrated on Vidovdan (St. Vitus Day), June, 28th. The Order has the icon of this saint, and it is being guarded by the Supreme Command of the Order.