Arab naval trade was contested by the Greeks, who tried to challenge Arab control of maritime trade between India and Egypt during the early Middle Ages. Arab trade persisted during the period, and Greek naval trade dwindled. There were a number of harbors on the Arabian Peninsula, some of which remain in operation. The most important harbors in the eastern Arabian Peninsula were Al-Ubulla, Gerrha and Sohar (Oman). The most important southern harbors were Mocha, Qanī (now Bi'r `Ali, Yemen), Aden, and Muska (Samharam). The most important western ports included al-Sha'ibah, Aylah (Aqaba) and Luwikat Kuma (al-Hawra'). A sea route used by Arabs to reach India ran from The Euphrates of Maysan to Debal on the Indus River. They would also sail from al-Ubulla, passing Oman and on to India. Those who traveled from the harbors of Yemen, such as the Qanī and Muza of Gerrha, would sail directly to India without needing to stop and resupply.