In the 18th century, Europe was beginning to exert its milit ar y power and political influence across the globe. Th er e wer e three imp ortant geographica l arenas whe re this warfa re took place. The first was in Europe itself, wher e struggles between va rio us dynast ies led to gradua l cha nges in the balan ce of power. The second area lay in and aro und the ove rseas colonies belon ging to the Europea n power s - mainl y in the A mericas and Indi a.Th e th ird broad area lay along Chris tian Europe 's fro ntie r with the Muslim Ottom an Empire. Fro m the 14th century onward, Ottoman armies and fleets had continua lly threaten ed E uro pe. A ll the countries of the Balkan peninsul a, up to and including pr esent-day Hungary and Rom ani a, wer e part of the Ottom an Empire. In 1683, Vienna was actua lly bes iege d by Ottom an ar mies. During the 18th century, however , a decisive shift took place: Ottoman forces were de feat ed in a number of wars and the lon g process of dismantl ing thi s great empire began .