In this article, at first the concept of war in Islam has been explained briefly. Afterwards, the reasons of the first conquests that occur in the period of al-Khulafa al-Rashidun have been studied from the political, economical and religious aspects alongside with the detailed examples. In addition, in this study it has been dealt with the peacefully conquests that directed by the Arabs consisting of the rudest humanbeings in the world by means of Islam