When World War I broke out in 1914, the King and his Prime Minister Venizelos both preferred to maintain a neutral stance, in spite of Greece's treaty of alliance with Serbia, which had been attacked by Austria-Hungary as the first belligerent action of the conflict. But when the Allies asked for Greek help in the Dardanelles campaign of 1915, offering Cyprus in exchange, their diverging views became apparent: Constantine had been educated in Germany, was married to Sophia of Prussia, sister of Kaiser Wilhelm, and was convinced of the Central Powers' victory. Venizelos, on the other hand, was an ardent anglophile, and believed in an Allied victory.