The War of the Fourth Coalition (1806–07) involving Prussia, Russia, Saxony, Sweden and the United Kingdom against France formed within months of the collapse of the previous coalition. In August 1806, King Frederick William III of Prussia made the decision to go to war independently of any other great power except neighbouring Russia. Another course of action might have involved declaring war the previous year and joining Austria and Russia. This might have contained Napoleon and prevented the Allied disaster in the Battle of Austerlitz. In any event, the Russian Army, an ally of Prussia, still remained far away when Prussia declared war.