Deim Zubeir, from the Arabic ديم الزبير ["Daim az-Zubayr"], commonly translated as the "Camp of Zubeir", is the historically established but highly controversial name of Uyujuku town in the Western Bahr el Ghazal of the Republic of South Sudan, located in the Western Bahr El Ghazal part of the country, some 70 km from the border with the Central African Republic (CAR), near the Biri tributary of the River Chel. Due to different transliterations from the Arabic, the name components are also spelled in various combinations Dem, Dehm, Deym, Dam, Daym or Daim, and Zubair, Zubayr, Zoubair, Zoubeir, Zoubayr, Zobeir, Ziber, Zebehr, or Zubier, respectively. The historical remains of the slave camp have been designated a potential UNESCO World Heritage Centre site. In the collective memory of South Sudanese people, the very name Deim Zubeir rings as a synonym for millennia of slavery, at least since Pharaonic times. Stefano Santandrea (1966) had written a lexicon and grammatical sketch of the Mboto dialect of the Birri language as spoken in Deim Zubeir. History Domination by Dar Fur Sultanate (18th to mid-19th century) Little is known about historical developments at the location before the second half of the 19th century. Even its original name is not clear: according to the pioneering scholar of Sudan history Richard Leslie Hill, it was called "Bayyu", which is the same name as reportedly remembered by Zubeir Rahma. In slight contrast, Gerasimos Makri writes that the old name was "Bāya" and Douglas H. Johnson mentions it as "Gbaya". Edward Thomas elaborates that "Gbaya" is another name for "Kresh", which is in turn the "name for several groups with origin stories in Western Bahr al-Ghazal and present-day CAR." Historiography has established that at least since the 18th century people in the Western part of the Bahr El Ghazal river system area were constantly on the move because of external pressures. Social groups were rather small and shifted frequently to avoid attacks from powerful neighbours who already possessed European weapons and forcefully expanded the trans-Saharan and Nilotic trading networks into the hinterlands for the exploitation of copper, ivory, ostrich feathers and slaves. From the northern side, this pressure increased since the early 17th century with the rise of the Dar Fur Sultanate, as it established a patron-client relationship over the lowlands which became known as Dar Fertit. While Dar means 'home of', Fertit does not describe any ethnic group,