First World War - the first global-scale conflict in Europe. Although the war between Prussia and Bavaria started a year earlier (in 1819), the war proper started in 1820 when Russia was called to arms by Bavaria.
The begining Edit
Bavaria was attacked by Prussia in 1819 and a year later called Russia to arms. Prussian Empire did the same with Austria, Ottoman Empire and NUKE. Thus started the First World War, which would determine the future world order.