<Dl> <Dt> Naval theaters </Dt> </Dl> <Ul> <Li> U-boat </Li> <Li> Atlantic Ocean </Li> <Li> Mediterranean </Li> </Ul> <P> Although considerable conflict took place outside Europe, the European theatre was the main theatre of operations during World War I and was where the war began and ended . During the four years of conflict, battle was joined by armies of unprecedented size equipped with new mechanized technologies, leaving millions dead or wounded . </P> <P> The European theatre is divided into four main theatres of operations: the Western Front, the Eastern Front, the Italian Front, and the Balkans Front . Not all of Europe involved in the war . Nor did fighting take place throughout all of the major combatants territory . The United Kingdom was nearly untouched by the war . Most of France was unaffected, as was most of Germany and Italy . </P>

Where did most of the fighting take place in ww1