The rise of the Ottoman Empire and its spread in Asia Minor and the Balkans coincided with the decline of the Seljuk Turks and the Byzantine Empire. Early Ottoman buildings, for almost two centuries after 1300, were characterized by a blending of Ottoman culture and indigenous architecture, and the pendentive dome was used throughout the empire. The Byzantine dome form was adopted and further developed. Ottoman architecture made exclusive use of the semi-spherical dome for vaulting over even very small spaces, influenced by the earlier traditions of both Byzantine Anatolia and Central Asia. The smaller the structure, the simpler the plan, but mosques of medium size were also covered by single domes. The earliest Ottoman mosques were single oblong rooms with either simple tiled pitched roofs of wood or a wooden interior dome. Most of these wooden domes have been lost to fires and replaced by flat ceilings. The earliest masonry domes covered square single room mosques, the archetype of Ottoman architecture. Examples include the Mosque of Orhan Gazi in Gebze and Karagöz Bey Mosque in Mostar. This domed-square unit is the defining element of the three basic Ottoman mosque plans: the single unit mosque, multi-unit mosque, and eyvan (or "iwan") mosque.