After 622, the Islamic culture takes a politic and military role in the Arabian peninsula. Battle after battle, it takes through violence Syria (635), Egypt and Armenia (639), north Africa (642), and finally Constantinople (717). Nonetheless, first Muslim battles in Europe appeared in 714, in France. They took Narbonne and kept it for 40 years. In 717, they made a siege of Toulouse. After multiples battles, it is Charles Martel who managed to repeal the Muslims who fled to the actual Spain. Yet Muslims continued punctual attacks for 300 years. Between 1178 and 1197 (19 years!), they destroyed Toulon, killing or taking away the entire population.
In parallel crusades took place in order to take back the lands seized by Muslims. Crusades were a defense against the invader and its goal was to move the battle around Jerusalem, which would therefore keep in peace Europeans. It is interesting to note that crusaders paid for themselves and were totally free to choose whether to fight or not. The first tax (decime – 10%) was then implemented to support the war effort. For the most interested, conscription, or obligatory mobilization, was actually implemented after french revolution (law Jourdan-Delbrel in 1798).
At that time, Spain and Italy were conquered by Muslims until the years 1200 and 1300. In 1830, France decided to repeal all Muslims and launched the conquest of Algeria, which eventually became a colony.
A summary of all battles can be found in this video from Bill Warner, his comments are self explanatory: https://www.youtube.com/watch?v=I_To-cV94Bo
So, is Islam about peace?