Hasan Tahsin Pasha (1845–1918) was a senior Ottoman military officer, who served in Yemen and in the First Balkan War. Hasan Tahsin was born in Messaria (modern Molista)[citation needed]. During his youth, he attended and graduated from the Greek Zosimaia School at Ioannina, and spoke Greek fluently. He began service as a gendarme ca. 1870 in Katerini, and later joined the Ottoman Army as an NCO. He soon received a commission as an officer, and by 1881 he commanded the Ottoman Gendarmerie at Ioannina. During the Greco-Turkish War of 1897, he commanded the 6th Trabzon Division, and around 1900, he was placed as garrison commander of Thessaloniki. In 1908–1910, he served as the governor of Yemen before returning to Thessaloniki, where he assumed the post of CO of the III Corps with the rank