context: At the beginning of the 19th century the Ottoman Empire included all of the Balkan Peninsula north to the southern edge of the Hungarian Plain, but by 1914 had lost all of it except Constantinople and Eastern Thrace to the rise of Balkan nationalism, which saw the independence of Greece, Serbia, the Danubian Principalities and Bulgaria. Up until 1912 the Ottomans retained a band of territory including Albania, Macedonia and Thrace, which were lost in the two Balkan Wars of 1912–13.
question: ఒట్టోమన్లు అల్బేనియా, మాసిడోనియా, థ్రేస్ భూభాగాన్ని ఎప్పుడు కోల్పోయారు?
answers: the two Balkan Wars of 1912–13