The study aims in general to reconsider the role of dervishes in early Ottoman society and politics within the framework of the march culture during the fourteenth century. It deals with the socio-religious conditions of the marches and with special emphasis of the non-orthodox nature of the folk-Islam in general and of the beliefs and practices of the dervishes in Anatolia in particular. The role of the dervishes in the socio-political developments of the formative period of the Ottoman state is studied in this context mainly through the hagiographic literature or velayetnames / menakıbnames of the fifteenth century in comparison with the earliest chronicles as well as other contemporary or near-contemporary sources. The examination of two velayetnames, Velayetname of Seyyit Ali Sultan (Kızıldeli) and of Abdal Musa, reveals the fact that the dervishes of the Ottoman marches are generally portrayed in such sources as ghazi dervishes or warrior dervishes sometimes within the Islamic concept of Holy War. Whether or not this portrayal of dervishes as “Holy warrior” corresponds to the historical reality, it is clear that the dervishes of the period were indeed very much involved in the early Ottoman military activities in the marches. It is also clear from the sources that they played a significant role in legitimizing the Ottoman power among the Turko-Muslim population of Anatolia, mostly nomadic in character, through an effective preaching activity. In addition, their role as colonizer in the newly conquered lands is once more confirmed by the sources used in this study. As a conclusion, the study points out that the dervishes and the early Ottomans appear to be the sides of a complex relationship of a story of mutual interest, both recognizing the power of each other and benefiting from it.