Joan of Rethel was a noblewoman from the 12th century, known for her role in the Crusades. Born into the influential family of the Counts of Rethel, she was the daughter of Hugh II of Rethel and Melisende of Montlhéry. Joan's life was marked by her marriage to Baldwin IV of Jerusalem, which strengthened ties between her family and the Kingdom of Jerusalem. Joan's significance lies in her contributions to the political landscape of the time. Her marriage produced a daughter, Sibylla of Jerusalem, who later became queen. Joan's lineage played a crucial role in the succession of the Kingdom of Jerusalem during a tumultuous period in history.