Noba is a term found in a number of historical sources discussing ancient and Medieval Nubia

Nubia

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...

. Its exact meaning is uncertain, with ancient sources themselves seeming confused about the region south of Egypt

Egypt

Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

. Most likely it refers to two separate groups: the Nuba

Nuba

Nuba is a collective term used here for the peoples who inhabit the Nuba Mountains, in Sudan, Africa. Although the term is used to describe them as if they composed a single group, the Nuba are multiple distinct peoples and speak different languages...

 a people from southeast of Nubia and a people later known as the Nobatae, a group of unknown origin who invaded Nubia during the decline of Meroe

Meroë

Meroë Meroitic: Medewi or Bedewi; Arabic: and Meruwi) is an ancient city on the east bank of the Nile about 6 km north-east of the Kabushiya station near Shendi, Sudan, approximately 200 km north-east of Khartoum. Near the site are a group of villages called Bagrawiyah...

 and most likely founded the kingdom of Nobatia

Nobatia

Nobatia or Nobadia was an ancient African Christian kingdom in Lower Nubia and subsequently a region of the larger Nubian Kingdom of Makuria...

and gave their name to Nubia itself.