Akçakoca Bey, known as one of Osman Bey's close friends and commanders, is the Ottoman Akıncı Bey, who had many conquests. Known as the "Conqueror of Kocaeli", Akçakoca Bey annexed Kandıra to the Ottoman lands between 1308 and 1317 during the reign of Orhan Bey, who was also his tutor at the age of the prince. In 1320, he organized raids to conquer Izmit and its surroundings, took the Aydos and Samandıra castles together with Konur Alp from the Byzantines, and placed his own soldiers. While Akçakoca Bey was continuing his raids towards Izmit, he lost his life in Babatepe near Kandıra. The mausoleum of Akçakoca Bey, who was buried on the hill where his tent is located on his will, is located in Kandıra, Babadağ.