The main theme of the series (Kurulus Osman) is the life History of Osman Bey, the son of Ertugrul Ghazi. This series includes and highlights all the strains, troubles he faced and how the Ottoman Empire was set up. Well known names such as Burak Ozcivit (Osman Bey), Ozge Torer (Bala Hatun), Ragip Savas (Dundar Bey) play their roles in the series. Starting after the completion of Dirilis Ertugrul, the series carry on with almost alike cast.

No matter how fictitious the series is based on, it successfully describes the life and provocations in Anatolia, motivated by Turkish and Islamic history. In the first episodes the connections between the Kayi tribe and Byzantine are exhibited. Osman Bey`s uncle Dundar Bey controlled the plain in the truancy of Ertugrul Ghazi. In Kurulus Osman Season 1, Dundar Bey intends to make a deal with Byzantium and earn more wealth for his tribe, but the things do not happen as he wanted. Byzantine governor Yorgopolos is murdered by a plan made by his wife and commander Kalanoz. Sofia, the governor`s wife, blames Osman Bey for this happening. Osman By runs away proving his guiltlessness. Meanwhile, Bamsi`s son Aybars is martyrized. This incident deeply affects Bamsi.