Deng Laka was born to a Dinka refugee family living among the Gaawar Nuer along the Zeraf Valley in what is now part of Jonglei state, South Sudan, in the mid-nineteenth century.
His mother and sisters were captured and sold into slavery by Nuaar Mer, a powerful man from the Radh clan of Gaawar, who was a contact point for the Arab merchants from the Ottoman empire.
[clarification needed] He waged a war against Nuaar Mer after his allies, the Arab merchants of Turco-Egyptian Sudan withdrew from Bahr el-Zaref.
[citation needed] Deng Laka then successfully led the Gaawar Nuer to the battle Mut Roal, and fought against the Twic Dinka and their Arab allies.
Deng Laka waged intermittent warfare against the Dinka who had also backed the slavers, and when floods in the Bahr al-Zaraf forced him to seek higher ground on the Duk ridge.