Nubia is a region along the Nile river, which is located in northern Sudan and southern Egypt. There were a number of small Nubian kingdoms throughout the Middle Ages, the last of which collapsed in 1504, when Nubia became divided between Egypt and the Sennar sultanate resulting in the Arabization of much of the Nubian population. Nubia was again united within Ottoman Egypt in the 19th century, and within Anglo-Egyptian Sudan from 1899 to 1956. The name Nubia is derived from that of the Noba people, nomads who settled the area in the 4th century, with the collapse of the kingdom of Meroë. The Noba spoke a Nilo-Saharan language, ancestral to Old Nubian. Old Nubian was mostly used in religious texts dating from the 8th and 15th centuries AD. Before the 4th century, and throughout classical antiquity, Nubia was known as Kush, or, in Classical Greek usage, included under the name Ethiopia (Aithiopia). Historically, the people of Nubia spoke at least two varieties of the Nubian language group, a subfamily which includes Nobiin (the descendant of Old Nubian), Kenuzi-Dongola, Midob and several related varieties in the northern part of the Nuba Mountains in South Kordofan. A variety Birgid was spoken (at least until 1970) north of Nyala in Darfur but is now extinct.