The Seventh Crusade's defining battle at Mansurah and the surrender of Louis IX's army afterward are described in detail by the eyewitness chronicler Jean de Joinville and by the historians who follow him, but none converts that narrative into a bounded total across combat losses, disease and the army's captivity.
What would resolve this A military historian's combined accounting of Mansurah's battle deaths, the army's losses to disease in the Nile Delta, and deaths among those held captive afterward.
OpenCrusading history, medieval military history.Christopher Tyerman, God's War: A New History of the Crusades