Bulgaria allied itself with Germany.
Bulgaria . The following years saw several conflicts with its neighbours , which prompted Bulgaria to align with Germany in both world wars . The Central Powers ( Mittelmächte Központi hatalmak İttifak Devletleri or Bağlaşma Devletleri Централни сили Tsentralni sili ) , consisting of Germany , , the Ottoman Empire and Bulgaria -- hence also known as the Quadruple Alliance ( Vierbund ) -- was one of the two main factions during World War I ( 1914 -- 18 ) . Germany ( listen ) , is a federal parliamentary republic in central-western Europe .