Kuyaba (Arabic: كويابة Kūyāba[1]) was one of the three centers of the Rus[1][2] or Saqaliba (early East Slavs) described in a lost book by Abu Zayd al-Balkhi (dating from ca.
920) and mentioned in works by some of his followers (Ibn Hawqal, Al-Istakhri, Hudud ul-'alam).
The two other centers were Slawiya (Arabic: صلاوية Ṣ(a)lāwiya)[1][2] (tentatively identified with the land of Ilmen Slavs, see Rus' Khaganate) and Arthaniya (Arabic: ارثانية ’Arṯāniya) (not properly explained).
They theorized that Kuyaba had been a union of Slavic tribes in the middle course of the Dnieper River centered on Kiev (now in Ukraine).
[3] Kuyaba, Slawiya, and Artaniya later merged to form the state of Kievan Rus', believed to include modern Belarus, Russia and Ukraine.