al-Ubulla, also known as Apologia, was a medieval port city in southern Iraq, located east of present-day Basra. It was founded by the Sassanid Persian emperor Ardashir I in the early 3rd century on the right bank of the Euphrates-Tigris estuary opening into the Persian Gulf, and it was known as Apologia to the Greeks. During the Muslim conquest of Persia, the Arab Rashidun general Utba ibn Ghazwan al-Mazini conquered the city from its 500-man Sassanid garrison, and it became a major port city with links to Bahrain, Oman, India, and China. Its garrison was later relocated to Basra, but al-Ubulla remained a major trade port until the Mongol Empire invaded the Middle East in the 13th century, upon which al-Ubulla became little more than a village and disappeared from the record.