During the Vienna Conference, Austria, France, and Austria formed an alliance and secretly signed the Vienna Treaty against Russia and Prussia on January 3, 1815. The purpose was to prevent Russia from gaining Poland and Prussia from gaining Saxony. The treaty stipulated that when one of the contracting parties was threatened and attacked, the other two countries should intervene and would provide 150,000 troops of military assistance. Bavaria, Hanover, the Netherlands and other countries joined the alliance one after another.