Isabelle of Hainault died in Paris on March 15, 1190, the day after giving birth to twin sons, Robert and Philip. Both infants died within days. Her final illness therefore belongs to a closely documented sequence of childbirth and family loss, but the surviving record does not establish a specific modern obstetric diagnosis. It would be speculative to identify a confirmed infection, hemorrhage or treatment failure. She was about nineteen and had already given birth to the future Louis VIII in 1187. That son secured the succession and survived her, while the twins did not. Earlier conflict with Philip II, including his attempt to repudiate her and the public sympathy she gained, had been resolved years before and should not replace the immediate circumstances of the final pregnancy. She was buried in Notre-Dame in Paris. The royal chronology and dynastic consequences are clearer than the exact events in the delivery chamber or the care attempted afterward. The supported ending is a rapid decline following the birth of twins, accompanied by the loss of the newborns, with her precise symptoms, attendants and last words not dependably preserved.