The Ottomans are scientific and industrious. They start the game with Masonry and Bronze Working and build Sipahi instead of cavalry. Fables and legends that feature the origins of the Ottoman Empire indicate that Osman, a Turkish tribesman, was the original ruler responsible for founding the civilization that nearly brought Christian Europe to its knees. Narratives indicate that Osman's tribe, the Kayi, fled west from the Mongols in the 13th century and took control of a freebooting army of nomads and Muslim peasants who inhabited the rugged stretch of wasteland along the Byzantine frontier. This band of refugees enjoyed close ties to Muslim guilds and religious brotherhoods in local towns that were led by Sheikh Edebali, who allowed Osman to form a tiny state around his castle of Karacahisar. Turkish warriors and religious leaders who also fled from the pagan Mongols in the east quickly populated this region, ruled by Osman. Osman directed his community through the Kara Su valley to seize Yenisehir, and establish it as the first true Ottoman capital. The Ottoman state emerged, poised above the fertile shores of the Sea of Marmara. Osman continued to wage a slow but persistent war against the Byzantine Empire who endeavored to defend their territories along the Asiatic shores that were opposite of Constantinople (now Istanbul). His first victory over a Byzantine army at Koyunhisar in 1301 AD perpetuated Osman's fame, and settlers flocked to Ottoman territory as a result. Osman extended his control over several other Byzantine fortresses, providing the Ottomans with strong bases from which they could lay siege to Bursa and Nicaea in northwest Anatolia. The pinnacle of Osman's reign occurred at the conquest of Bursa shortly before his death. Initially, Ottoman war tactics were no different than those used by the tribal Turks. They would first harass the foe with horse-archers, employing hit and run tactics, only closing in on the enemy when they became completely disorganized. Thus, the earliest Ottoman successes were won against isolated Byzantine garrisons, but rarely against a field army. In order to capture fortified towns the Ottomans ravaged the countryside and imposed blockades. Afterwards, the Ottomans would revive the town's trade and increase its population so that it could then be consolidated into the Empire as a productive