May 25, 735: Bede ("The Venerable"), father of English history, dies. In addition to his Ecclesiastical History of the English People (731), biographies of abbots, and Scripture commentaries, he wrote our primary source for the story of how Celtic and Roman Christianity clashed at the Synod of Whitby in 664 (see issue 60: How the Irish Were Saved and issue 72: How We Got Our History).
May 25, 1535: After holding Munster under siege for over a year, the army of the city's Roman Catholic bishop breaks in, capturing and killing the radical Anabaptists who had taken control. The Anabaptists had acted on the prophecy of Melchoir Hoffman (later modified by Jan Matthys) that Christ would soon return, and only Christians in Munster would survive. During the siege, Matthys and his followers became increasingly despotic and maniacal, enjoying excesses while the people starved and introducing wild innovations such as polygamy (see issue 61: The End of the World).
May 25, 1824: The Sunday and Adult Sunday School Union in Philadelphia establishes the American Sunday School Union. It purposed to use Sunday schools as a means to instill Christian and democratic values "wherever there is a population." In 1970 it changed its name to the American Missionary Society.
May 25, 1865: Evangelist and ecumenist John R. Mott is born in New York. He served 40 years with the Y.M.C.A. (while that organization was still aggressively evangelistic), chaired the 1910 Edinburgh Missionary Conference, and was named honorary president of the World Council of Churches at its inaugural session (see issue 65: The Ten Most Influential Christians of the Twentieth Century).