Now the king of Bulgaria, or the czar, as he prefers to call himself, is a German. (As these little countries won their independence from Turkey, they almost always called in foreign princes to be their kings. In this way it had come about that the king of Greece was a prince of Denmark, the king of Roumania was a German of the Hohenzollern family, while the czar of Bulgaria was a German of the Coburg family, the same family which has furnished England and Belgium with their kings.) The Bulgarians themselves are members of the Greek Catholic Church, and they have a very high regard for the czar of Russia, as the head of that church. Czar Ferdinand had no such feeling, however. He wanted to be the most powerful ruler in the Balkan states, and it made no difference to him which side helped him to gain his object. [Illustration: A Bomb-Proof Trench in the Western War Front] About this time, the Russians had been forced to retreat to a line running south from Riga, on the Baltic Sea, to the northern boundary of Roumania. The French and English had been pounding at the Dardanelles for some months, but the stubborn resistance of the Turks seemed likely to hold them out of Constantinople for a long time to come. The checked Italians had not been able to make much headway against the Austrians through the mountainous Alpine country where the fighting was taking place. In the west, the Germans were holding firmly against the attacks of the British and French. The czar of Bulgaria and his ministers, thinking that the German-Austrian-Turkish alliance could win with their help, flung their nation into its third war within four years. This happened in Octoher, 1915. Now at the close of the second Balkan war, when Serbia and Greece defeated Bulgaria, they made an alliance, by which each agreed to come to the help of the other in case either was attacked by Bulgaria. Roumania, too, was friendly to Greece and Serbia, rather than to treaty Bulgaria, for the Roumanians knew that Bulgaria was very anxious to get back the territory of which Roumania had robbed her, in the second Balkan war. In this way, the Quadruple Entente (Russia, Italy, France, and England) hoped that the entry of Bulgaria into the war, on the side of Germany and Turkey, would bring Greece and Roumania in on the other side.