Pibor River
...that the boundary between Sudan and Ethiopia was defined for the region near the Pibor River in 1899 by Major H.H. Austin and Major Charles W. Gwynn of the British Royal Engineers?
...that the boundary between <a href="./Sudan" id="mwow" rel="mw:WikiLink" title="Sudan">Sudan</a> and <a href="./Ethiopia" id="mwpA" rel="mw:WikiLink" title="Ethiopia">Ethiopia</a> was defined for the region near the <b id="mwpQ"><a href="./Pibor_River" id="mwpg" rel="mw:WikiLink" title="Pibor River">Pibor River</a></b> in <a href="./1899" id="mwpw" rel="mw:WikiLink" title="1899">1899</a> by Major H.H. Austin and Major Charles W. Gwynn of the British Royal Engineers?