Until the late Middle Ages, "Bahrain" referred to the region of Eastern Arabia that included Southern Iraq, Kuwait, Al-Hasa, Qatif, and Bahrain. The region stretched from Basra in Iraq to the Strait of Hormuz in Oman. This was Iqlīm al-Bahrayn's "Bahrayn Province." The exact date at which the term "Bahrain" began to refer solely to the Awal archipelago is unknown. The entire coastal strip of Eastern Arabia was known as "Bahrain" for a millennium. The island and kingdom were also commonly spelled '''Bahrein''' into the 1950s.