Abstract: Most western publications give July 24, 1900 as the date of the martyrdom of the Beligian missionary, Monsignor Ferdinand Hamer ( C. I. C. M. -Scheut) in Inner Mongolia, China. Hamer’s death was part of the Northern Boxer Incident that shocked the country and world. According to most accounts, his death occurred on the fifth day after his arrest on 20 July in the church of Ershisi Qingdi. However, previously overlooked Chinese archives of the Qing Dynasty indicate that the church was taken and the bishop arrested one day earlier on 19 July. Monsignor Hamer, therefore, was martyred on 23 July and not on 24 July. In the new millennium, it is necessary for scholars of missionary incidents in China, to reassess archival sources and historical publications. We should begin by clearing up such small misunderstandings as the date of the martyrdom of Monsignor Hamer before examining comprehensively and objectively other important historical obstacles to Sino-Vatican reconciliation.