<P> In March 1917, demonstrations in Petrograd culminated in the abdication of Tsar Nicholas II and the appointment of a weak Provisional Government, which shared power with the Petrograd Soviet socialists . This arrangement led to confusion and chaos both at the front and at home . The army became increasingly ineffective . </P> <Ol> <Li> Count Ottokar von Czernin </Li> <Li> Richard von Kühlmann </Li> <Li> Vasil Radoslavov </Li> </Ol> <Li> Count Ottokar von Czernin </Li> <Li> Richard von Kühlmann </Li>

When did the first world war end officially