Tirilye is a town in Bursa Province, Mudanya, Turkey, situated west of Mudanya. It is a township along the Marmara Sea shoreline. The area, which was inhabited since the 5th century BC, was formerly known as Τρίγλεια, Trigleia or Βρύλλειον, Brylleion in Greek. When demand for the products of Southern Marmara from the ancient world increased, ports have been constructed in Kios ( Gemlik), Kurşunlu, Apamea Myrlea( Mudanya), Siği ( Kumyaka), and Trilye (Zeytinbağı) and the region boomed. The most important historical structure in Trilye(Triglia) is that of the Byzantine Haghioi Theodoroi Church, known today as the Fatih Mosque. Mudanya, a residential and commercial development in this township is under state protection as a historical site.
Trilye has been an important religious center for Greek Orthodox Christians for a long time. Trilye is a first level protected area since 1980 because of the Byzantine and Ottoman architectural monuments and is considered as an open-air museum thanks to the historical buildings and houses. Osman Gazi’s Turkmens in Bursa and surroundings have started settling in this location from the beginning of the year 1303. Kaymak Oba, Mirza Oba and Çepni villages located at the back of Trilye are believed to have been established during this era. After Mudanya was conquered in 1321 Trilye’s ports and other ports in the region started being used. The land at the western parts of Bursa namely the area between current Minor Industry Area (Küçük Sanayi Bölgesi) and Uluabat Lake were very fertile. Grapes, cocoons and cereal crops were grown in this region. In addition the Tahtalı, Demirci and Doğancı regions had high quality wood used in the production of ships. There are signs proving a Genoese cargo boat has visited Trilye port in the 1330s.
Churches and monasteries were constructed in Trigleia and its surroundings on the patronage of Byzantine Emperors.
Only 2500 people currently live in the town. In the town are the ruins of old Byzantine churches. Old Greek houses built at the end of the 19th century line what few streets are left. This town is under the protection by the Ministry of Culture so no one can destroy the old houses or rebuild them in a different style than the original one. The place is famous for its olives and had historically been inhabited by Greek artisans engaged in the silk trade. 'Zeytingbagi' means 'olive yard'.